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Golubeva EA, Lavrov MI, Veremeeva PN, Vyunova TV, Shevchenko KV, Topchiy MA, Asachenko AF, Palyulin VA. New Allosteric Modulators of AMPA Receptors: Synthesis and Study of Their Functional Activity by Radioligand-Receptor Binding Analysis. Int J Mol Sci 2023; 24:10293. [PMID: 37373440 DOI: 10.3390/ijms241210293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/09/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
The synthetic approaches to three new AMPA receptor modulators-derivatives of 1,11-dimethyl-3,6,9-triazatricyclo[7.3.1.13,11]tetradecane-4,8,12-trione-had been developed and all steps of synthesis were optimized. The structures of the compounds contain tricyclic cage and indane fragments necessary for binding with the target receptor. Their physiological activity was studied by radioligand-receptor binding analysis using [3H]PAM-43 as a reference ligand, which is a highly potent positive allosteric modulator of AMPA receptors. The results of radioligand-binding studies indicated the high potency of two synthesized compounds to bind with the same targets as positive allosteric modulator PAM-43 (at least on AMPA receptors). We suggest that the Glu-dependent specific binding site of [3H]PAM-43 or the receptor containing this site may be one of the targets of the new compounds. We also suggest that enhanced radioligand binding may indicate the existence of synergistic effects of compounds 11b and 11c with respect to PAM-43 binding to the targets. At the same time, these compounds may not compete directly with PAM-43 for its specific binding sites but bind to other specific sites of this biotarget, changing its conformation and thereby causing a synergistic effect of cooperative interaction. It can be expected that the newly synthesized compounds will also have pronounced effects on the glutamatergic system of the mammalian brain.
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Affiliation(s)
- Elena A Golubeva
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Mstislav I Lavrov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Polina N Veremeeva
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Tatiana V Vyunova
- Laboratory of Molecular Pharmacology of Peptides, Institute of Molecular Genetics, National Research Centre Kurchatov Institute, 123182 Moscow, Russia
| | - Konstantin V Shevchenko
- Laboratory of Molecular Pharmacology of Peptides, Institute of Molecular Genetics, National Research Centre Kurchatov Institute, 123182 Moscow, Russia
| | - Maxim A Topchiy
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Andrey F Asachenko
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Vladimir A Palyulin
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
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2
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Zamani N, Hassanian-Moghaddam H, Zamani N. Strategies for the treatment of acute benzodiazepine toxicity in a clinical setting: the role of antidotes. Expert Opin Drug Metab Toxicol 2022; 18:367-379. [PMID: 35875992 DOI: 10.1080/17425255.2022.2105692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Although not a potentially life-threatening poisoning, benzodiazepine (BZD) intoxication may be life-threatening in special situations/populations or those with background diseases. AREAS COVERED The aim of this review is to evaluate all possible treatment options available in the literature for the management of benzodiazepine poisoning with special attention to antidote administration. We conducted a literature search using PubMed, Google Scholar, EMBASE, and Cochrane central register from 1 January 1980 to 10 November 2021 using keywords 'benzodiazepine,' 'poisoning,' 'toxicity,' 'intoxication,' and 'treatment.' EXPERT OPINION Careful patient selection, ideally by a clinical toxicologist, may decrease the complications of flumazenil and add to its efficacy. The cost-to-benefit ratio should be considered in every single patient who is a candidate for flumazenil administration. In case a decision has been made to administer flumazenil, careful consideration of the possible contraindications is essential. We recommend slow administration of low doses of flumazenil (0.1 mg/minute) to avoid complications or withhold the administration with development of first signs of adverse effects. The main treatment of benzodiazepine toxicity is conservative with administration of activated charcoal, monitoring of the vital signs, prevention of aspiration and development of deep vein thrombosis due to prolonged immobilization, and respiratory support.
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Affiliation(s)
- Nasim Zamani
- Department of Clinical Toxicology, Loghman-Hakim Hospital, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Social Determinants Health Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Hassanian-Moghaddam
- Department of Clinical Toxicology, Loghman-Hakim Hospital, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Social Determinants Health Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Naghmeh Zamani
- Department of Biology, Tehran North Branch, Islamic Azad University, Tehran, Iran
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Borrego-Muñoz P, Ospina F, Quiroga D. A Compendium of the Most Promising Synthesized Organic Compounds against Several Fusarium oxysporum Species: Synthesis, Antifungal Activity, and Perspectives. Molecules 2021; 26:3997. [PMID: 34208916 PMCID: PMC8271819 DOI: 10.3390/molecules26133997] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/25/2021] [Accepted: 06/27/2021] [Indexed: 11/17/2022] Open
Abstract
Vascular wilt caused by F. oxysporum (FOX) is one of the main limitations of producing several agricultural products worldwide, causing economic losses between 40% and 100%. Various methods have been developed to control this phytopathogen, such as the cultural, biological, and chemical controls, the latter being the most widely used in the agricultural sector. The treatment of this fungus through systemic fungicides, although practical, brings problems because the agrochemical agents used have shown mutagenic effects on the fungus, increasing the pathogen's resistance. The design and the synthesis of novel synthetic antifungal agents used against FOX have been broadly studied in recent years. This review article presents a compendium of the synthetic methodologies during the last ten years as promissory, which can be used to afford novel and potential agrochemical agents. The revision is addressed from the structural core of the most active synthetic compounds against FOX. The synthetic methodologies implemented strategies based on cyclo condensation reactions, radical cyclization, electrocyclic closures, and carbon-carbon couplings by metal-organic catalysis. This revision contributes significantly to the organic chemistry, supplying novel alternatives for the use of more effective agrochemical agents against F. oxysporum.
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Affiliation(s)
| | | | - Diego Quiroga
- Bioorganic Chemistry Laboratory, Facultad de Ciencias Básicas y Aplicadas, Campus Nueva Granada, Universidad Militar, Nueva Granada, Cajicá 250247, Colombia; (P.B.-M.); (F.O.)
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4
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Ntoupa PSA, Papoutsis II, Dona AA, Spiliopoulou CA, Athanaselis SA. A fluorine turns a medicinal benzodiazepine into NPS: the case of flualprazolam. Forensic Toxicol 2021. [DOI: 10.1007/s11419-020-00565-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Abstract
Purpose
The purpose of this review is to summarize the existing knowledge on flualprazolam, a novel ‘designer’ benzodiazepine that derives from the fluorination of the phenyl moiety in the ortho-position of alprazolam.
Methods
An extensive literature search was carried out in PubMed, Google Scholar and World Wide Web using relevant keywords. All articles found were gathered, and the available information is presented.
Results
This article reviews the existing knowledge on chemistry, pharmacology, toxicology, prevalence and current legal status of flualprazolam. Moreover, forensic and clinical cases where flualprazolam was involved worldwide, as well as flualprazolam seizures, along with the methods for its determination in biological samples are presented.
Conclusions
The recent flualprazolam-related cases have raised concerns to regulatory authorities and international stakeholders suggesting that flualprazolam should be under international control. The urgent international control of flualprazolam, despite the limited information on clinical effects and pharmacologic characteristics available, is an important measure for the prevention of its increasing abuse worldwide.
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Orsolini L, Corkery JM, Chiappini S, Guirguis A, Vento A, De Berardis D, Papanti D, Schifano F. 'New/Designer Benzodiazepines': An Analysis of the Literature and Psychonauts' Trip Reports. Curr Neuropharmacol 2020; 18:809-837. [PMID: 31933443 PMCID: PMC7569319 DOI: 10.2174/1570159x18666200110121333] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/08/2019] [Accepted: 01/09/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND NPS belonging to the benzodiazepine (BZD) class, e.g., 'legal/designer BZDs'/'research chemicals', have recently emerged in the drug (mainly online/virtual) market. OBJECTIVE While certain NPS belonging to the BZD class possess pharmacological profiles similar to controlled pharmaceutical BZDs, clinical and pharmacological profiles of current emerging BZDs are still not well-described. Therefore, there is a need to increase clinicians'/public health knowledge/awareness, to incentive harm reduction strategies. METHOD A comprehensive overview was carried out by using the EMCDDA/EDND database regularly monitored by our research team, by specifically looking at the 'new BZDs' so far notified. Furthermore, given the limitation of peer-reviewed data published so far, a nonparticipant multilingual qualitative netnographic study was conducted to obtain further clinical/pharmacological/ toxicological data, including psychonauts' online trip reports. RESULTS First designer BZDs appeared as NPS around 2007. So far, 29 designer BZDs have been notified to the EMCDDA, being some of them extremely powerful, also at lower dosages. They are sold as tablets/powder/pellets/capsules/blotters/liquids, at very affordable prices, and variably administered. Some are also sold on the illicit drugmarket as counterfeit forms of traditional BZDs or as either adulterants or diluents in heroin or other synthetic opioids/cannabinoids. Nowadays, there is no guarantee of the quality of designer BZDs composition/purification and, hence, most NPS consumers may be inadvertently exposed to unsafe and harmful compounds. CONCLUSION Given the limited information on their pharmacology/toxicity, variations in dosage, onset of effects, combination of substances, potency, and general patient or individual variability, the concomitant use of these substances with other drugs entails several and unpredictable risks.
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Affiliation(s)
- Laura Orsolini
- Address correspondence to this author at the Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, AL10 9AB, Herts, UK; Villa Jolanda Hospital, Neomesia Mental Health, Villa Jolanda, Italy; Polyedra, Teramo, Italy; Tel: (+39) 392 3244643; E-mail:
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Halbeck E, Dumps C, Bolkenius D. [Drugs for intravenous induction of anesthesia: ketamine, midazolam and synopsis of current hypnotics]. Anaesthesist 2019; 67:617-634. [PMID: 30069734 DOI: 10.1007/s00101-018-0469-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ketamine and midazolam form the endpoint of a series of articles about intravenous induction of anesthesia . Both substances can be used as single induction hypnotic drugs; however, in practice, this is unusual. Both substances, with the exception of a few very specific indications and clinical situations, are more frequently used in combination or with one of the more common alternatives propofol, barbiturates and etomidate. The reasons are the activity and side effects of both substances and their positive characteristics are used more as a supplement. In the concluding comparison the five discussed induction hypnotics are judged against each other. The use in certain clinical constellations and in special patient populations is evaluated individually for each substance. It is highlighted which drug appears most appropriate in which situation. As methohexital is nowadays only administered in very few clinical situations, this substance is not included in the comparative assessment.
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Affiliation(s)
- E Halbeck
- Klinik für Anästhesiologie und Operative Intensivmedizin, Klinikum Augsburg, Stenglinstr. 2, 86156, Augsburg, Deutschland.
| | - C Dumps
- Klinik für Anästhesiologie und Operative Intensivmedizin, Klinikum Augsburg, Stenglinstr. 2, 86156, Augsburg, Deutschland
| | - D Bolkenius
- Klinik für Anästhesiologie und Operative Intensivmedizin, Klinikum Augsburg, Stenglinstr. 2, 86156, Augsburg, Deutschland
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Chen M, Zhang X, Chen Y, Sun W, Wang Z, Huang C, Hu G, Chen R. Comparison of the inhibitory effect of ketoconazole, voriconazole, fluconazole, and itraconazole on the pharmacokinetics of bosentan and its corresponding active metabolite hydroxy bosentan in rats. Xenobiotica 2019; 50:280-287. [PMID: 31199171 DOI: 10.1080/00498254.2019.1628321] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Mengchun Chen
- Department of Pharmacy, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xufei Zhang
- Laboratory of Animal Centre, Wenzhou Medical University, Wenzhou, China
| | - Yijie Chen
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
| | - Wei Sun
- Department of Pharmacy, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zhe Wang
- Department of Pharmacy, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
| | - Chengke Huang
- Department of Pharmacy, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
| | - Guoxin Hu
- School of Pharmacy, Wenzhou Medical University, Wenzhou, China
| | - Ruijie Chen
- Department of Pharmacy, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
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Furugen A, Nishimura A, Kobayashi M, Umazume T, Narumi K, Iseki K. Quantification of eight benzodiazepines in human breastmilk and plasma by liquid-liquid extraction and liquid-chromatography tandem mass spectrometry: Application to evaluation of alprazolam transfer into breastmilk. J Pharm Biomed Anal 2019; 168:83-93. [PMID: 30798209 DOI: 10.1016/j.jpba.2019.02.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 02/07/2019] [Accepted: 02/08/2019] [Indexed: 11/25/2022]
Abstract
Breastfeeding is strongly encouraged for infant and maternal health. Benzodiazepines (BZDs) are widely prescribed drugs for symptoms, such as anxiety and insomnia, which many women could experience during the postpartum period. However, limited information is currently available to evaluate the transfer of different BZDs into breastmilk. In order to assess the proprieties of this medication during breastfeeding, robust and sensitive analytical methods to quantify BZDs are required. For this purpose, we developed a method for quantification of BZDs, including alprazolam, bromazepam, clonazepam, clotiazepam, etizolam, flunitrazepam, lorazepam, and CM7116 (a metabolite of ethyl loflazepate), in human breastmilk and plasma using liquid chromatography/tandem mass spectrometry (LC/MS/MS). Sample preparation was performed by a simple liquid-liquid extraction (LLE) with ethyl acetate. For sample preparation of CM7116, the pretreatment process to completely obtain the metabolite was added before the LLE step. The BZDs were separated by a C18 column using a gradient elution of acetonitrile in aqueous ammonium acetate solution, and were detected in the positive ion electrospray mode with multiple reaction monitoring (MRM). Lower limits of quantification (LLOQs) in breastmilk ranged from 0.25 to 0.5 ng/mL, and those in plasma ranged from 0.5 to 1.0 ng/mL. The intra-day and inter-day precision, and accuracy of data were assessed and found to be acceptable. The developed method was successfully applied to measure the concentration of alprazolam in breastmilk and plasma, which were donated by a lactating woman who had been regularly treated with alprazolam. Milk to plasma (M/P) ratios were calculated as 0.52 (before oral administration) and 0.49 (2 h after administration) 3 days after delivery. The M/P ratio 1 month after delivery was calculated as 0.41 (2 h after administration). We estimated that the relative infant dose (RID) values of alprazolam ranged from 3.11 to 4.61%.
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Affiliation(s)
- Ayako Furugen
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome, Kita-ku, Sapporo 060-0812, Japan
| | - Ayako Nishimura
- Department of Pharmacy, Hokkaido University Hospital, Sapporo, Japan
| | - Masaki Kobayashi
- Department of Pharmacy, Hokkaido University Hospital, Sapporo, Japan.
| | - Takeshi Umazume
- Department of Obstetrics, Hokkaido University Hospital, Sapporo, Japan
| | - Katsuya Narumi
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome, Kita-ku, Sapporo 060-0812, Japan
| | - Ken Iseki
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome, Kita-ku, Sapporo 060-0812, Japan; Department of Pharmacy, Hokkaido University Hospital, Sapporo, Japan.
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9
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Manchester KR, Lomas EC, Waters L, Dempsey FC, Maskell PD. The emergence of new psychoactive substance (NPS) benzodiazepines: A review. Drug Test Anal 2017; 10:37-53. [DOI: 10.1002/dta.2211] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 04/11/2017] [Accepted: 04/26/2017] [Indexed: 01/17/2023]
Affiliation(s)
- Kieran R. Manchester
- School of Applied Sciences, Queensgate Campus; University of Huddersfield; Huddersfield UK
| | - Emma C. Lomas
- School of Applied Sciences, Queensgate Campus; University of Huddersfield; Huddersfield UK
| | - Laura Waters
- School of Applied Sciences, Queensgate Campus; University of Huddersfield; Huddersfield UK
| | - Fiona C. Dempsey
- MedAnnex Ltd, 1 Summerhall Place; Techcube 3.5; Edinburgh EH9 1PL UK
| | - Peter D. Maskell
- School of Science, Engineering and Technology; Abertay University; Dundee UK
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10
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Kampfrath T, Peng P, Vairavan V, Lee D. Benzodiazepine in a urine specimen without drug metabolites. Lab Med 2015; 46:164-7. [PMID: 25918198 DOI: 10.1309/lmig49ydfsunq2ys] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
CLINICAL HISTORY PATIENT 41-year-old Hispanic woman. Chief Complaint: Pain in the neck, joints, and shoulders that started in August 2013. History of Present Illness: The patient has a history of psychiatric illness. Her primary care physician from an outside facility had prescribed alprazolam (Xanax) to treat her depression. The patient reported that in 2011 she experienced pain in the right side of her back and was diagnosed with sciatica. In addition, she was diagnosed with systemic lupus erythematosus (SLE) based on a positive finding for antinuclear antibodies (ANA) and double-stranded DNA (ds-DNA). She had not consulted a rheumatologist before this visit, nor had she received any medication for these conditions. Her recent history of symptoms included photosensitivity, painful aphthous ulcers, transient rashes, joint pain, myalgias, and bruising. The results of the most recent evaluation of her SLE serology revealed negative ANA and ds-DNA results. The current medications that the patient has been prescribed at Santa Clara Valley Medical Center include lamotrigine (Lamictal), sertraline (Zoloft), and gabapentin (Neurontin). In April 2014, the patient requested additional pain medication, such as hydrocodone/acetaminophen (Norco), during her physician visit. Consequently, as part of her pain management therapy agreement to ensure compliance,(1) she was subjected to a urine toxicology drug screening. At this time, her urine specimen, from an unwitnessed collection, tested positive for benzodiazepines using the Syva EMIT immunoassay (Siemens AG, Munich, Germany) at the cutoff of 200 ng/mL. However, results of a confirmatory test conducted via gas chromatography-mass spectrometry (GC/MS) did not identify any benzodiazepine metabolites in her urine but instead revealed the presence of a parent drug, alprazolam. Further, the same specimen tested positive for metronidazole. A visual inspection of the specimen revealed crystals on the bottom of the cup. In December 2013, this patient had tested positive for α-hydroxyalprazolam (an alprazolam metabolite; limit of detection, 10 ng/mL) and methamphetamine. At that time, she explained her positive urine-drug-test result by stating that "somebody had put something in my drink." Family history: Her father has been diagnosed with gout, knee osteoarthritis, and enlarged heart. Her brother has been diagnosed with clinical depression. Social history: Divorced; 3 children in the custody of their father; reported having smoked 0.5 packs of cigarettes per day for 20 years; denied any alcohol intake or illicit drug use.
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Affiliation(s)
- Thomas Kampfrath
- Department of Pathology and Laboratory Medicine, Santa Clara Valley Medical Center, San Jose, California
| | - Penny Peng
- Department of Pathology and Laboratory Medicine, Santa Clara Valley Medical Center, San Jose, California
| | - Valli Vairavan
- Department of Pathology and Laboratory Medicine, Santa Clara Valley Medical Center, San Jose, California
| | - Dayong Lee
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, Florida
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Chetty M, Rose RH, Abduljalil K, Patel N, Lu G, Cain T, Jamei M, Rostami-Hodjegan A. Applications of linking PBPK and PD models to predict the impact of genotypic variability, formulation differences, differences in target binding capacity and target site drug concentrations on drug responses and variability. Front Pharmacol 2014; 5:258. [PMID: 25505415 PMCID: PMC4244809 DOI: 10.3389/fphar.2014.00258] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 11/04/2014] [Indexed: 02/06/2023] Open
Abstract
This study aimed to demonstrate the added value of integrating prior in vitro data and knowledge-rich physiologically based pharmacokinetic (PBPK) models with pharmacodynamics (PDs) models. Four distinct applications that were developed and tested are presented here. PBPK models were developed for metoprolol using different CYP2D6 genotypes based on in vitro data. Application of the models for prediction of phenotypic differences in the pharmacokinetics (PKs) and PD compared favorably with clinical data, demonstrating that these differences can be predicted prior to the availability of such data from clinical trials. In the second case, PK and PD data for an immediate release formulation of nifedipine together with in vitro dissolution data for a controlled release (CR) formulation were used to predict the PK and PD of the CR. This approach can be useful to pharmaceutical scientists during formulation development. The operational model of agonism was used in the third application to describe the hypnotic effects of triazolam, and this was successfully extrapolated to zolpidem by changing only the drug related parameters from in vitro experiments. This PBPK modeling approach can be useful to developmental scientists who which to compare several drug candidates in the same therapeutic class. Finally, differences in QTc prolongation due to quinidine in Caucasian and Korean females were successfully predicted by the model using free heart concentrations as an input to the PD models. This PBPK linked PD model was used to demonstrate a higher sensitivity to free heart concentrations of quinidine in Caucasian females, thereby providing a mechanistic understanding of a clinical observation. In general, permutations of certain conditions which potentially change PK and hence PD may not be amenable to the conduct of clinical studies but linking PBPK with PD provides an alternative method of investigating the potential impact of PK changes on PD.
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Affiliation(s)
| | - Rachel H Rose
- Simcyp Limited (a Certara Company), Blades Enterprise Centre Sheffield, UK
| | - Khaled Abduljalil
- Simcyp Limited (a Certara Company), Blades Enterprise Centre Sheffield, UK
| | - Nikunjkumar Patel
- Simcyp Limited (a Certara Company), Blades Enterprise Centre Sheffield, UK
| | - Gaohua Lu
- Simcyp Limited (a Certara Company), Blades Enterprise Centre Sheffield, UK
| | - Theresa Cain
- Simcyp Limited (a Certara Company), Blades Enterprise Centre Sheffield, UK
| | - Masoud Jamei
- Simcyp Limited (a Certara Company), Blades Enterprise Centre Sheffield, UK
| | - Amin Rostami-Hodjegan
- Simcyp Limited (a Certara Company), Blades Enterprise Centre Sheffield, UK ; Manchester Pharmacy School, University of Manchester Manchester, UK
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Baneyx G, Parrott N, Meille C, Iliadis A, Lavé T. Physiologically based pharmacokinetic modeling of CYP3A4 induction by rifampicin in human: Influence of time between substrate and inducer administration. Eur J Pharm Sci 2014; 56:1-15. [DOI: 10.1016/j.ejps.2014.02.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 01/07/2014] [Accepted: 02/02/2014] [Indexed: 11/16/2022]
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Lappin G, Noveck R, Burt T. Microdosing and drug development: past, present and future. Expert Opin Drug Metab Toxicol 2013; 9:817-34. [PMID: 23550938 DOI: 10.1517/17425255.2013.786042] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Microdosing is an approach to early drug development where exploratory pharmacokinetic data are acquired in humans using inherently safe sub-pharmacologic doses of drug. The first publication of microdose data was 10 years ago and this review comprehensively explores the microdose concept from conception, over the past decade, up until the current date. AREAS COVERED The authors define and distinguish the concept of microdosing from similar approaches. The authors review the ability of microdosing to provide exploratory pharmacokinetics (concentration-time data) but exclude microdosing using positron emission tomography. The article provides a comprehensive review of data within the peer-reviewed literature as well as the latest applications and a look into the future, towards where microdosing may be headed. EXPERT OPINION Evidence so far suggests that microdosing may be a better predictive tool of human pharmacokinetics than alternative methods and combination with physiologically based modelling may lead to much more reliable predictions in the future. The concept has also been applied to drug-drug interactions, polymorphism and assessing drug concentrations over time at its site of action. Microdosing may yet have more to offer in unanticipated directions and provide benefits that have not been fully realised to date.
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Affiliation(s)
- Graham Lappin
- University of Lincoln, Brayford Pool, Lincoln, LN6 7TS, UK.
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Goteti K, Brassil PJ, Good SS, Garner CE. Estimation of Human Drug Clearance Using Multiexponential Techniques. J Clin Pharmacol 2013; 48:1226-36. [DOI: 10.1177/0091270008320369] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Obach RS. Pharmacologically active drug metabolites: impact on drug discovery and pharmacotherapy. Pharmacol Rev 2013; 65:578-640. [PMID: 23406671 DOI: 10.1124/pr.111.005439] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Metabolism represents the most prevalent mechanism for drug clearance. Many drugs are converted to metabolites that can retain the intrinsic affinity of the parent drug for the pharmacological target. Drug metabolism redox reactions such as heteroatom dealkylations, hydroxylations, heteroatom oxygenations, reductions, and dehydrogenations can yield active metabolites, and in rare cases even conjugation reactions can yield an active metabolite. To understand the contribution of an active metabolite to efficacy relative to the contribution of the parent drug, the target affinity, functional activity, plasma protein binding, membrane permeability, and pharmacokinetics of the active metabolite and parent drug must be known. Underlying pharmacokinetic principles and clearance concepts are used to describe the dispositional behavior of metabolites in vivo. A method to rapidly identify active metabolites in drug research is described. Finally, over 100 examples of drugs with active metabolites are discussed with regard to the importance of the metabolite(s) in efficacy and safety.
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Affiliation(s)
- R Scott Obach
- Pfizer Inc., Eastern Point Rd., Groton, CT 06340, USA.
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Morgan PT, Kehne JH, Sprenger KJ, Malison RT. Retrograde effects of triazolam and zolpidem on sleep-dependent motor learning in humans. J Sleep Res 2010; 19:157-64. [PMID: 19682231 DOI: 10.1111/j.1365-2869.2009.00757.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Peter T Morgan
- Department of Psychiatry, Yale University, 34 Park Street, New Haven, CT 06519, USA.
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Kato M, Chiba K, Ito T, Koue T, Sugiyama Y. Prediction of Interindividual Variability in Pharmacokinetics for CYP3A4 Substrates in Humans. Drug Metab Pharmacokinet 2010; 25:367-78. [DOI: 10.2133/dmpk.dmpk-09-rg-038] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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19
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Bialer M. Pharmacodynamic and pharmacokinetic characteristics of intravenous drugs in status epilepticus. Epilepsia 2009; 50 Suppl 12:44-8. [DOI: 10.1111/j.1528-1167.2009.02348.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Mahmood I. Application of fixed exponent 0.75 to the prediction of human drug clearance: an inaccurate and misleading concept. ACTA ACUST UNITED AC 2009; 24:57-81. [PMID: 19354001 DOI: 10.1515/dmdi.2009.24.1.57] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Considering the controversy surrounding the exponent of 0.75 for the prediction of human drug clearance and lack of any systematic evaluation of the aforementioned proposal, the objective of this study was to determine whether the exponent 0.75 is indeed the most suitable exponent for the prediction of human drug clearance as compared to allometric scaling using the rule of exponents (ROE). Three methods were used to predict human drug clearance. Besides evaluating the exponent of 0.75, an arbitrarily selected exponent of 0.65 was also tested. ROE was also used to predict human drug clearance, and predicted values by all three methods were compared with observed human drug clearance. The results indicate that the exponent 0.75 is not the best approach for the prediction of human drug clearance. Both exponents 0.75 and 0.65 predicted human drug clearance with uncertainty, although on average the prediction of human drug clearance by 0.65 was better than the exponent 0.75. ROE provided far more accurate prediction of human drug clearance than either of the exponents. Although exponent 0.75 occasionally provided a good prediction of human drug clearance for a given drug for a given species, overall, the method is highly erratic and unreliable.
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Affiliation(s)
- Iftekhar Mahmood
- Office of Blood Review & Research, Center for Biologic Evaluation and Research, Food & Drug Administration, 1451 Rockville Pike, MD 20852, USA.
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21
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Nutt D, Mandel F, Baldinetti F. Early onset anxiolytic efficacy after a single dose of pregabalin: double-blind, placebo- and active-comparator controlled evaluation using a dental anxiety model. J Psychopharmacol 2009; 23:867-73. [PMID: 18635690 DOI: 10.1177/0269881108094722] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To evaluate acute onset of anxiolytic activity using a dental anxiety model, 89 patients were randomised to double-blind single dose pregabalin 150 mg, alprazolam 0.5 mg or placebo 4 h before a scheduled dental procedure. A Dental Anxiety Total score >12 (moderate-to-severe) without meeting Diagnostic and Statistical Manual of Mental Disorders (Fourth edition) (DSM-IV) anxiety disorder criteria was required. Efficacy and safety, assessed 2, 2.5, 3, 3.5 and 4 h postdose, included 100 mm Visual Analogue Scale for Anxiety (VAS-Anxiety; primary outcome), 100 mm VAS-Sedation and Time-to-Onset of Action Scale (TOAS), a patient-rated anti-anxiety drug-benefit scale (no [0] to full benefit [10]). Mixed model analysis found significantly greater VAS-A improvement slopes for pregabalin (t = -2.47; P = 0.014) and alprazolam (t = -2.39; P = 0.018). There was a significant improvement versus placebo in the TOAS from 2 h through endpoint in alprazolam patients and from 3 h onward in pregabalin patients. Pregabalin produced significantly greater increases in VAS-Sedation versus placebo from 2.5 h through 4 h (2 h onward for alprazolam). Notably, there was a higher correlation between TOAS and VAS-Sedation (r = +0.58) than VAS-Anxiety (r = -0.50) on Spearman's analysis. The majority of Adverse Effects (AEs) were mild, and the most frequent for pregabalin, alprazolam, and placebo, respectively, were fatigue (N = 7, 7, 3), dizziness (N = 6, 3, 3), attention disturbance (N = 3, 1, 0), somnolence (N = 3, 0, 0), feeling abnormal (N = 0, 2, 0) and balance disorder (N = 0, 2, 0). These results suggest that onset of clinically meaningful anxiolytic effect after single-dose pregabalin occurs within the first 3-4 h. Additional research is needed to determine whether anxiolytic effect occurs in generalized anxiety disorder populations by day 1 or within 3-4 h post-first dose.
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Affiliation(s)
- D Nutt
- Psychopharmacology Unit, University of Bristol, Bristol, UK.
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22
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Poisnel G, Dhilly M, Boisselier RL, Barre L, Debruyne D. Comparison of Five Benzodiazepine-Receptor Agonists on Buprenorphine-Induced μ-Opioid Receptor Regulation. J Pharmacol Sci 2009; 110:36-46. [DOI: 10.1254/jphs.08249fp] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Baas JMP, Mol N, Kenemans JL, Prinssen EP, Niklson I, Xia-Chen C, Broeyer F, van Gerven J. Validating a human model for anxiety using startle potentiated by cue and context: the effects of alprazolam, pregabalin, and diphenhydramine. Psychopharmacology (Berl) 2009; 205:73-84. [PMID: 19415242 PMCID: PMC2695548 DOI: 10.1007/s00213-009-1516-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Accepted: 03/11/2009] [Indexed: 11/01/2022]
Abstract
BACKGROUND Fear-potentiated startle has been suggested as a translational model for evaluating efficacy of anxiolytic compounds in humans. Several known anxiolytic compounds have been tested as well as several putative anxiolytics. Because results of these studies have been equivocal, the aim of the present study was to examine another pharmacological permutation of the human potentiated startle model by comparing two anxiolytic agents to a non-anxiolytic sedative and placebo. METHODS Twenty healthy volunteers participated in a double-blind, placebo-controlled, cross-over study with four sessions in which they received single doses of the anxiolytics alprazolam (1 mg) and pregabalin (200 mg), as well as diphenhydramine (50 mg) as a non-anxiolytic sedative control and placebo. The design included a cued shock condition that presumably evokes fear and an unpredictable shock context condition presumably evoking anxiety. RESULTS None of the treatments reliably reduced either fear- or anxiety-potentiated startle. Alprazolam and diphenhydramine reduced overall baseline startle. Alprazolam was found to only affect contextual anxiety in a statistical significant way after two subjects who failed to show a contextual anxiety effect in the placebo condition were excluded from the analysis. Pregabalin did not significantly affect any of the physiological measures. DISCUSSION The negative findings from this study are discussed in terms of methodological differences between designs and in variability of startle both between and within study participants. CONCLUSION Even though fear-potentiated startle may be used to translate preclinical evidence to human populations, methodological issues still hamper the application of this model to early screening of putative anxiolytic drugs.
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Affiliation(s)
- J. M. P. Baas
- Department of Experimental Psychology, Faculty of Social Sciences, Utrecht University, Van Unnik Building, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands
| | - N. Mol
- Department of Experimental Psychology, Faculty of Social Sciences, Utrecht University, Van Unnik Building, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands
| | - J. L. Kenemans
- Department of Experimental Psychology, Faculty of Social Sciences, Utrecht University, Van Unnik Building, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands
| | - E. P. Prinssen
- CNS Research, F. Hoffmann-La Roche, Clinical Development, Basel, Switzerland
| | - I. Niklson
- CNS Research, F. Hoffmann-La Roche, Clinical Development, Basel, Switzerland ,Present Address: Swissmedic, Bern, Switzerland
| | - C. Xia-Chen
- Centre for Human Drug Research, Leiden, The Netherlands
| | - F. Broeyer
- Centre for Human Drug Research, Leiden, The Netherlands
| | - J. van Gerven
- Centre for Human Drug Research, Leiden, The Netherlands
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García-Algar O, López-Vílchez MA, Martín I, Mur A, Pellegrini M, Pacifici R, Rossi S, Pichini S. Confirmation of gestational exposure to alprazolam by analysis of biological matrices in a newborn with neonatal sepsis. Clin Toxicol (Phila) 2008; 45:295-8. [PMID: 17453885 DOI: 10.1080/15563650601072191] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Different biological matrices are suitable for drug testing in newborns presenting with an acute withdrawal syndrome. CASE REPORT The newborn of a mother reporting alprazolam use during pregnancy presented with respiratory distress and clinical features consistent with neonatal withdrawal syndrome or neonatal sepsis of vertical transmission. Alprazolam and its main metabolite (alpha-hydroxyalprazolam) were detected in cord serum, neonatal urine and also in neonatal hair, meconium and placenta, accounting for both acute and chronic exposure to this benzodiazepine during intrauterine life. At the same time, the clinical diagnosis of neonatal sepsis was confirmed by isolation of Streptococcus agalactiae from otic cultures. The infant received oxygen therapy and antibiotic treatment and recovered completely at the age of 11 days. Although no congenital anomalies or behavioral alterations were diagnosed during hospitalization, periodic follow-ups were requested to check for potential long-term effects of prenatal exposure to alprazolam.
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Abuse liability of intra-nasal midazolam in inhaled-cocaine abusers. Eur Neuropsychopharmacol 2008; 18:723-8. [PMID: 18620849 DOI: 10.1016/j.euroneuro.2008.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 05/14/2008] [Accepted: 05/14/2008] [Indexed: 11/23/2022]
Abstract
Intra-nasally instilled benzodiazepines have been proposed for acute anxiety episodes. However, routes with faster absorption may increase abuse liability. This study compared abuse liability of intra-nasal midazolam between subjects with a history of intra-nasal drug abuse and non-psychiatric subjects on a single-blind randomized controlled trial. Thirty-one inhaled-cocaine abusers and 34 normal volunteers received either 1 mg intra-nasal midazolam or active placebo. Visual analogue scales assessing desire to repeat the experience (ER) and Experience Liking (EL) assessed abuse liability. Profile analysis for repeated measures showed a significant effect of time over ER (F([5,57])=3.311, p=0.011) and EL (F([5,57])=3.947, p=0.004), diagnostic group (cocaine abusers scoring higher on both - F([5,57])=5.229, p=0.026; F([5,57])=4.946, p=0.030), regardless of the administered substance. It is concluded that the intra-nasal route does not seem to pose risks for non-psychiatric individuals, but it may represent a risk in itself for subjects with a history of drug abuse through this path.
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Rawden HC, Carlile DJ, Tindall A, Hallifax D, Galetin A, Ito K, Houston JB. Microsomal prediction ofin vivoclearance and associated interindividual variability of six benzodiazepines in humans. Xenobiotica 2008; 35:603-25. [PMID: 16192111 DOI: 10.1080/00498250500162870] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The intrinsic clearances (CLint) of midazolam, triazolam, diazepam, nordiazepam, flunitrazepam and alprazolam were determined from two liver banks (n=21) by formation kinetics of ten metabolites. A literature-collated database of in vivo CLint values (811 subjects) was used to assess predictions and variability. The in vivo clearance of six benzodiazepines was generally underpredicted by in vitro data and the degree of bias was in agreement with a database of structurally diverse compounds (n=37). The variability observed for in vitro clearances (11--19--fold for midazolam, diazepam and nordiazepam in liver bank 1; 101--269--fold for triazolam, flunitrazepam and alprazolam in liver bank 2) exceeded the in vivo variability for the same compounds (4--59 and 10--29, respectively). This mismatch may contribute to the bias in microsomal predictions and it highlights the need for careful selection of representative livers for human liver banks.
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Affiliation(s)
- H C Rawden
- School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Manchester, UK
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Abstract
This article aims to bring to the fore, issues regarding the interface of psychiatry and renal failure. Depression, anxiety, suicide and delirium are common complications observed in patients with renal failure. Pharmacological management of these problems need stringent monitoring on part of the psychiatrist. This article examines the various complications that may be observed in patients with renal failure while discussing treatment approaches and also emphasizing the need for interdisciplinary team work in improving the quality of life of patients with renal failure and those on dialysis.
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Affiliation(s)
- A. De Sousa
- Consultant Psychiatrist, Get Well Clinic, Mumbai, Maharashtra, India
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Douzenis A, Michopoulos I, Economopoulos T, Lykouras L, Soldatos CR. Sublingual use of olanzapine in combination with alprazolam to treat agitation in a terminally ill patient receiving parenteral nutrition. Eur J Cancer Care (Engl) 2007; 16:289-90. [PMID: 17508951 DOI: 10.1111/j.1365-2354.2006.00735.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper reports the case of a 64-year-old man who was receiving parenteral nutrition after repeated operations due to stomach cancer. Olanzapine (orally disintegrating tablets) in combination with alprazolam was used successfully to relieve this terminally ill patient's anxiety and tension improving his relationship with his physicians and his daily life.
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Affiliation(s)
- A Douzenis
- Department of General Hospital Psychiatry, Athens University Medical School, Attikon Hospital, Athens, Greece.
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Sternieri E, Coccia CPR, Pinetti D, Guerzoni S, Ferrari A. Pharmacokinetics and interactions of headache medications, part II: prophylactic treatments. Expert Opin Drug Metab Toxicol 2007; 2:981-1007. [PMID: 17125412 DOI: 10.1517/17425255.2.6.981] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The present part II review highlights pharmacokinetic drug-drug interactions (excluding those of minor severity) of medications used in prophylactic treatment of the main primary headaches (migraine, tension-type and cluster headache). The principles of pharmacokinetics and metabolism, and the interactions of medications for acute treatment are examined in part I. The overall goal of this series of two reviews is to increase the awareness of physicians, primary care providers and specialists regarding pharmacokinetic drug-drug interactions (DDIs) of headache medications. The aim of prophylactic treatment is to reduce the frequency of headache attacks using beta-blockers, calcium-channel blockers, antidepressants, antiepileptics, lithium, serotonin antagonists, corticosteroids and muscle relaxants, which must be taken daily for long periods. During treatment the patient often continues to take symptomatic drugs for the attack, and may need other medications for associated or new-onset illnesses. DDIs can, therefore, occur. As a whole, DDIs of clinical relevance concerning prophylactic drugs are a limited number. Their effects can be prevented by starting the treatment with low dosages, which should be gradually increased depending on response and side effects, while frequently monitoring the patient and plasma levels of other possible coadministered drugs with a narrow therapeutic range. Most headache medications are substrates of CYP2D6 (e.g., beta-blockers, antidepressants) or CYP3A4 (e.g., calcium-channel blockers, selective serotonin re-uptake inhibitors, corticosteroids). The inducers and, especially, the inhibitors of these isoenzymes should be carefully coadministered.
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Affiliation(s)
- Emilio Sternieri
- University of Modena and Reggio Emilia, Division of Toxicology and Clinical Pharmacology, Headache Centre, University Centre for Adaptive Disorders and Headache, Section Modena II, Largo del Pozzo 71, Modena, Italy
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Ujiie Y, Fukasawa T, Yasui-Furukori N, Suzuki A, Tateishi T, Otani K. Rifampicin Markedly Decreases Plasma Concentration and Hypnotic Effect of Brotizolam. Ther Drug Monit 2006; 28:299-302. [PMID: 16778710 DOI: 10.1097/01.ftd.0000200010.33430.0e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The purpose of the present study was to examine the effects of rifampicin on the single oral dose pharmacokinetics and pharmacodynamics of brotizolam. Thirteen healthy male volunteers received rifampicin 450 mg/day, or matched placebo, for 7 days in a double-blind randomized crossover manner. On the sixth day they received a single oral 0.5-mg dose of brotizolam, and blood sampling was performed for 24 hours, together with an assessment of psychomotor function using the Digit Symbol Substitution Test and the Stanford Sleepiness Scale. Rifampicin treatment significantly (P<0.001) decreased the peak plasma concentration (69%), total area under the plasma concentration-time curve (90%) and elimination half-life (79%) of brotizolam. Rifampicin significantly increased the area under the score-time curve of the Digit Symbol Substitution Test (P<0.01), and decreased that of the Stanford Sleepiness Scale (P<0.05). The present study suggests that rifampicin markedly decreases plasma concentration and hypnotic effect of brotizolam and, therefore, this combination is not recommended in clinical practice.
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Affiliation(s)
- Yukihiro Ujiie
- Department of Psychiatry, Yamagata University School of Medicine, Yamagata, Japan
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Brown HS, Ito K, Galetin A, Houston JB. Prediction of in vivo drug-drug interactions from in vitro data: impact of incorporating parallel pathways of drug elimination and inhibitor absorption rate constant. Br J Clin Pharmacol 2006; 60:508-18. [PMID: 16236041 PMCID: PMC1884945 DOI: 10.1111/j.1365-2125.2005.02483.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
AIMS Success of the quantitative prediction of drug-drug interactions via inhibition of CYP-mediated metabolism from the inhibitor concentration at the enzyme active site ([I]) and the in vitro inhibition constant (K(i)) is variable. The aim of this study was to examine the impact of the fraction of victim drug metabolized by a particular CYP (f(mCYP)) and the inhibitor absorption rate constant (k(a)) on prediction accuracy. METHODS Drug-drug interaction studies involving inhibition of CYP2C9, CYP2D6 and CYP3A4 (n = 115) were investigated. Data on f(mCYP) for the probe substrates of each enzyme and k(a) values for the inhibitors were incorporated into in vivo predictions, alone or in combination, using either the maximum hepatic input or the average systemic plasma concentration as a surrogate for [I]. The success of prediction (AUC ratio predicted within twofold of in vivo value) was compared using nominal values of f(mCYP) = 1 and k(a) = 0.1 min(-1). RESULTS The incorporation of f(mCYP) values into in vivo predictions using the hepatic input plasma concentration resulted in 84% of studies within twofold of in vivo value. The effect of k(a) values alone significantly reduced the number of over-predictions for CYP2D6 and CYP3A4; however, less precision was observed compared with the f(mCYP). The incorporation of both f(mCYP) and k(a) values resulted in 81% of studies within twofold of in vivo value. CONCLUSIONS The incorporation of substrate and inhibitor-related information, namely f(mCYP) and k(a), markedly improved prediction of 115 interaction studies with CYP2C9, CYP2D6 and CYP3A4 in comparison with [I]/K(i) ratio alone.
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Affiliation(s)
- Hayley S Brown
- School of Pharmacy & Pharmaceutical Sciences, University of Manchester, Manchester M13 9PL, UK
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Tokairin T, Fukasawa T, Yasui-Furukori N, Aoshima T, Suzuki A, Inoue Y, Tateishi T, Otani K. Inhibition of the metabolism of brotizolam by erythromycin in humans: in vivo evidence for the involvement of CYP3A4 in brotizolam metabolism. Br J Clin Pharmacol 2006; 60:172-5. [PMID: 16042670 PMCID: PMC1884921 DOI: 10.1111/j.1365-2125.2005.02380.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
AIMS To obtain in vivo evidence for the involvement of cytochrome P450 (CYP) 3A4 in the metabolism of brotizolam. METHODS Fourteen healthy male volunteers received erythromycin 1200 mg day(-1) or placebo for 7 days in a double-blind randomized crossover manner. On the 6th day they received a single oral 0.5-mg dose of brotizolam, and blood samplings were performed for 24 h. RESULTS Erythromycin treatment significantly increased the peak plasma concentration (P < 0.05), total area under the plasma concentration-time curve (P < 0.01), and elimination half-life (P < 0.01) of brotizolam. CONCLUSIONS The present study provides in vivo evidence for the involvement of CYP3A4 in brotizolam metabolism.
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Affiliation(s)
- Takaki Tokairin
- Department of Psychiatry, Yamagata University School of MedicineYamagata, Japan
| | - Takashi Fukasawa
- Department of Psychiatry, Yamagata University School of MedicineYamagata, Japan
| | - Norio Yasui-Furukori
- Department of Clinical Pharmacology, Hirosaki University School of MedicineHirosaki, Japan
| | - Toshiaki Aoshima
- Department of Psychiatry, Yamagata University School of MedicineYamagata, Japan
| | - Akihito Suzuki
- Department of Psychiatry, Yamagata University School of MedicineYamagata, Japan
| | - Yoshimasa Inoue
- Pharmaceutical Research Division, Mitsubishi PharmaFukuoka, Japan
| | - Tomonori Tateishi
- Department of Clinical Pharmacology, Hirosaki University School of MedicineHirosaki, Japan
| | - Koichi Otani
- Department of Psychiatry, Yamagata University School of MedicineYamagata, Japan
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Obach RS, Walsky RL, Venkatakrishnan K, Gaman EA, Houston JB, Tremaine LM. The utility of in vitro cytochrome P450 inhibition data in the prediction of drug-drug interactions. J Pharmacol Exp Ther 2005; 316:336-48. [PMID: 16192315 DOI: 10.1124/jpet.105.093229] [Citation(s) in RCA: 302] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The accuracy of in vitro inhibition parameters in scaling to in vivo drug-drug interactions (DDI) was examined for over 40 drugs using seven human P450-selective marker activities in pooled human liver microsomes. These data were combined with other parameters (systemic C(max), estimated hepatic inlet C(max), fraction unbound, and fraction of the probe drug cleared by the inhibited enzyme) to predict increases in exposure to probe drugs, and the predictions were compared with in vivo DDI gathered from clinical studies reported in the scientific literature. For drugs that had been tested as precipitants of drug interactions for more than one P450 in vivo, the order of inhibitory potencies in vitro generally aligned with the magnitude of the in vivo interactions. With the exception of many drugs known to be mechanism-based inactivators, the use of in vitro IC(50), the fraction of the affected drug metabolized by the target enzyme [f(m(CYP))] and an estimate of free hepatic inlet C(max), was generally successful in identifying those drugs that cause at least a 2-fold increase in the exposure to P450 marker substrate drugs. For CYP3A, incorporation of inhibition of both hepatic and intestinal metabolism was needed for the prediction of DDI. Many CYP3A inhibitors showed a different inhibitory potency for three different CYP3A marker activities; however, these differences generally did not alter the conclusions regarding whether a drug would cause a CYP3A DDI in vivo. Overall, these findings support the conclusion that P450 in vitro inhibition data are valuable in designing clinical DDI study strategies and can be used to predict the magnitudes of DDI.
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Affiliation(s)
- R Scott Obach
- Pfizer Global Research and Development, Groton Laboratories, MS4088, Groton, CT 06340, USA.
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Reddy A, Heimbach T, Freiwald S, Smith D, Winters R, Michael S, Surendran N, Cai H. Validation of a semi-automated human hepatocyte assay for the determination and prediction of intrinsic clearance in discovery. J Pharm Biomed Anal 2005; 37:319-26. [PMID: 15708673 DOI: 10.1016/j.jpba.2004.09.030] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2003] [Accepted: 09/13/2004] [Indexed: 11/18/2022]
Abstract
An automated high throughput human hepatocyte assay has been established with a 96-well format using a Tecan Genesistrade mark Workstation. Validation of this assay was performed with nine commercially available compounds and an additional 10 Pfizer compounds with varying hepatic extraction ratios (E(H)) ranging from 0.02 to approximately 1. The incubation conditions in the automated assay are readily and precisely controlled and cell viability of over 80% was achieved in the automated assay further confirming its utility for absorption, distribution, metabolism, and excretion (toxicity) (ADME (T)) screening. The results of the nine commercial compounds correlate with both manually executed (R(2)=0.97) and literature reported experimental results (R(2)=0.93). Overall, measured E(H)s were within two-fold of the literature values for approximately 90% of the 19 compounds tested. Additionally, good inter- and intra-day reproducibility was observed for all the 19 compounds. In conclusion, an automated and robust assay suitable for simultaneously testing up to 48 compounds with multiple time points has been validated. Throughput of 192 compounds per run can be achieved using 384-well plates to meet increasing needs in drug discovery. Currently, this automated assay is used to support early discovery profiling towards lead optimization of various discovery targets/programs.
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Affiliation(s)
- Anita Reddy
- Department of Pharmacokinetics, Dynamics, and Metabolism, Pfizer Global Research and Development, Michigan Laboratories, 2800 Plymouth Road, Ann Arbor, MI 48105, USA
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35
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Abstract
A rare and unusual case of hallucinations following triazolam administration is reported. A review of the literature suggests that hallucinations following triazolam are rare; this is the first report of such a reaction when triazolam was used for oral conscious sedation in dentistry. A discussion of dental implications follows with emphasis on complete medical history evaluation before administering oral sedatives. We conclude that the proper selection of oral sedation candidates, coupled with recognition and management of adverse events, is essential.
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Affiliation(s)
- Jason H Goodchild
- Department of Diagnostic Sciences, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA.
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36
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Abstract
There are many benefits of breast-feeding both for the infant and for the mother. Nursing mothers who are also taking medications or exposed to environmental hazards may be confronted with a difficult choice to discontinue nursing or maternal medication or risk potential harm to the infant. Frequently, these decisions are made without sufficient information or understanding of the factors influencing exposure. The current review explores two indices of exposure, together with their pharmacokinetic determinants. Both of the indices include the milk to serum (M/S) concentration ratio for a given drug and the volume of milk consumed. The first exposure term, EI(Dose), expresses neonatal dose as a percentage of maternal dose and is inversely related to the maternal systemic clearance. By contrast, the second exposure term, EI(Conc), expresses infant concentration as a percentage of maternal concentration and is inversely related to the infant systemic clearance. Issues related to intersubject variation in M/S (e.g., colostrum vs. mature milk, fore vs. hind milk) and infant clearance (e.g., ontogeny of elimination pathways, pharmacogenetics) and their role in modulating exposure are also discussed.
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Affiliation(s)
- Patrick J McNamara
- College of Pharmacy, University of Kentucky, Lexington, Kentucky 40536, USA.
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Araki K, Yasui-Furukori N, Fukasawa T, Aoshima T, Suzuki A, Inoue Y, Tateishi T, Otani K. Inhibition of the metabolism of etizolam by itraconazole in humans: evidence for the involvement of CYP3A4 in etizolam metabolism. Eur J Clin Pharmacol 2004; 60:427-30. [PMID: 15232663 DOI: 10.1007/s00228-004-0789-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2004] [Accepted: 05/08/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To clarify the involvement of cytochrome P450 (CYP) 3A4 in the metabolism of etizolam. METHODS The effects of itraconazole, a potent and specific inhibitor of CYP3A4, on the single oral dose pharmacokinetics and pharmacodynamics of etizolam were examined. Twelve healthy male volunteers received itraconazole (200 mg/day) or placebo for 7 days in a double-blind randomized crossover manner, and on the 6th day they received a single oral 1-mg dose of etizolam. Blood samplings and evaluation of psychomotor function using the Digit Symbol Substitution Test and Stanford Sleepiness Scale were conducted up to 24 h after etizolam dosing. Plasma concentration of etizolam was measured by means of high-performance liquid chromatography. RESULTS Itraconazole treatment significantly increased the total area under the plasma concentration-time curve (AUC; 213+/-106 ng rectangle h/ml versus 326+/-166 ng rectangle h/ml, P<0.001) and the elimination half-life (12.0+/-5.4 h versus 17.3+/-7.4 h, P<0.01) of etizolam. The 90% confidence interval of the itraconazole/placebo ratio of the total AUC was 1.38-1.68, indicating a significant effect of itraconazole. No significant change was induced by itraconazole in the two pharmacodynamic parameters. CONCLUSION The present study suggests that itraconazole inhibits the metabolism of etizolam, providing evidence that CYP3A4 is at least partly involved in etizolam metabolism.
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Affiliation(s)
- K Araki
- Department of Neuropsychiatry, Yamagata University School of Medicine, 990-9585 Yamagata, Japan
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38
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Cohen LM, Tessier EG, Germain MJ, Levy NB. Update on Psychotropic Medication Use in Renal Disease. PSYCHOSOMATICS 2004; 45:34-48. [PMID: 14709759 DOI: 10.1176/appi.psy.45.1.34] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Renal failure is a common medical condition, and many patients have comorbid psychiatric disorders. In this review, which is intended as a resource for consultation psychiatrists, the authors discuss pharmacokinetic considerations and provide information about the use of individual psychotropic medications in patients with renal disease. Most psychotropic medications are fat soluble, easily pass the blood-brain barrier, are not dialyzable, are metabolized primarily by the liver, and are excreted mainly in bile. Consequently, the majority of these drugs can be safely used with the end-stage renal disease population.
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Affiliation(s)
- Lewis M Cohen
- Psychiatri Consultation Service adn Renal Transplantation Service, Baystate Medical Center, Springfield, MA 01199, USA.
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39
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Turner JV, Maddalena DJ, Cutler DJ. Pharmacokinetic parameter prediction from drug structure using artificial neural networks. Int J Pharm 2004; 270:209-19. [PMID: 14726136 DOI: 10.1016/j.ijpharm.2003.10.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Simple methods for determining the human pharmacokinetics of known and unknown drug-like compounds is a much sought-after goal in the pharmaceutical industry. The current study made use of artificial neural networks (ANNs) for the prediction of clearances, fraction bound to plasma proteins, and volume of distribution of a series of structurally diverse compounds. A number of theoretical descriptors were generated from the drug structures and both automated and manual pruning were used to derive optimal subsets of descriptors for quantitative structure-pharmacokinetic relationship models. Models were trained on one set of compounds and validated with another. Absolute predicted ability was evaluated using a further independent test set of compounds. Correlations for test compounds ranged from 0.855 to 0.992. Predicted values agreed closely with experimental values for total clearance, renal clearance, and volume of distribution, while predictions for protein binding were encouraging. The combination of descriptor generation, ANNs, and the speed and success of this technique compared with conventional methods shows strong potential for use in pharmaceutical product development.
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Affiliation(s)
- Joseph V Turner
- Faculty of Pharmacy, The University of Sydney, Sydney 2006, Australia.
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40
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Abstract
Depressive and anxiety disorders appear during the transplant process due to psychological stressors, medications and physiological disturbances. Treatment is necessary to prevent impact on patient compliance, morbidity and mortality. Psychotropic medications provide an effective option, although most are only available as oral formulations. Because of this, they are more susceptible to alterations in pharmacokinetic behaviour arising from organ dysfunction in the pretransplant period. Kinetics are also an issue when considering potential drug-drug interactions before and after transplantation. Prior to transplant, organ dysfunction can change the pharmacokinetic behaviour of some psychotropic agents, requiring adjustment of dosage and schedules. Thoracic or abdominal organ failure may reduce drug absorption through disturbances in intestinal motility, perfusion and function. Cirrhotic patients experience increased drug bioavailability due to portosystemic shunting, and thus dosage is adjusted downward. In contrast, dosage needs to be raised when peripheral oedema expands the drug distribution volume for hydrophilic and protein-bound agents. Drug clearance for most psychotropic medications is dependent upon hepatic metabolism, which is often disrupted by endstage organ disease. Selection of drugs or their dosage may need to be adjusted to lower the risk of drug accumulation. Further adjustments in dosage may be called for when renal failure accompanies thoracic or abdominal organ failure, resulting in further impairment of clearance. Studies regarding the treatment of anxiety and depressive disorders in the medically ill are limited in number, but recommendations are possible by review of clinical and pharmacokinetic data. Selective serotonin reuptake inhibitors are well tolerated and efficacious for depression, panic disorder and post-traumatic stress disorder. Adjustments in dosage are required when renal or hepatic impairment is present. Among them, citalopram and escitalopram appear to have the least risk of drug-drug interactions. Paroxetine has demonstrated evidence supporting its use with generalised anxiety disorder. Venlafaxine is an alternative option, beneficial in depression, post-traumatic stress and generalised anxiety disorders. Nefazodone may also be considered, but there is some risk of hepatotoxicity and interactions with immunosuppressant drugs. Mirtazapine still needs to be studied further in anxiety disorders, but can be helpful for depression accompanied by anorexia and insomnia. Bupropion is effective in the treatment of depression, but data are sparse about its use in anxiety disorders. Psychostimulants are a unique approach if rapid onset of antidepressant action is desired. Acute or short-term anxiolysis is obtained with benzodiazepines, and selection of particular agents entails consideration of distribution rate, half-life and metabolic route.
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Affiliation(s)
- Catherine C Crone
- Department of Psychiatry, Inova Fairfax Hospital, Falls Church, Virginia, USA.
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41
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Christensen HD, Gonzalez CL, Rayburn WF. Effects from prenatal exposure to alprazolam on the social behavior of mice offspring. Am J Obstet Gynecol 2003; 189:1452-7. [PMID: 14634585 DOI: 10.1067/s0002-9378(03)00756-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The purpose of this study was to conduct, in a randomized placebo-controlled manner, social behavior testing on mice offspring that were exposed prenatally to alprazolam. STUDY DESIGN A previously described, clinically relevant dose of 0.32 mg/kg of alprazolam (n=8 mice) or a placebo (n=9 mice) was given to gravid C57BL/6 mice by gavage on gestational day 18. Social play, sleep/wake patterns, and male aggression of the exposed offspring were assessed during prejuvenile, juvenile, and adult periods. RESULTS Alprazolam did not produce treatment differences in pregnancy outcomes or in dam-pup interactions. Compared with the placebo group, alprazolam-exposed offspring demonstrated less desire to escape (P<.01), more desire to remain alone (P<.02), and shorter periods of being awake (P<.03) on PND 17. Alprazolam-exposed male offspring exhibited more aggression on food restriction (P<.01) and on cage changing (P<.01). CONCLUSION Mice offspring that were exposed prenatally to alprazolam demonstrated more individual rather than group activities, avoidance of open areas, and aggression in males. Correlation of these findings in humans is encouraged.
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Affiliation(s)
- H Dix Christensen
- Department of Obstetrics and Gynecology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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42
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Mahaguna V, Talbert RL, Peters JI, Adams S, Reynolds TD, Lam FYW, Williams RO. Influence of hydroxypropyl methylcellulose polymer on in vitro and in vivo performance of controlled release tablets containing alprazolam. Eur J Pharm Biopharm 2003; 56:461-8. [PMID: 14602191 DOI: 10.1016/s0939-6411(03)00116-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The purpose of this study was to investigate the influence of hydroxypropyl methylcellulose (HPMC) molecular weight on pharmacokinetic and pharmacodynamic parameters of controlled release formulations containing alprazolam. Tablet formulations contained alprazolam, excipients, and either HPMC K4MP or HPMC K100LVP. A ten patient in vivo clinical trial using a randomized, open-label, four-way crossover design was conducted in the fed and fasted states. Plasma alprazolam concentrations were determined for 72 h. The pharmacodynamic effects of alprazolam were monitored using subject rated sedation on visual analogue scale for wakefulness, observer rated sedation, and symbol digit modalities test (SDMT). Results indicated that the tablet formulations containing either HPMC K4MP or HPMC K100LVP had similar dissolution profiles, and the dissolution profiles did not change through 6 months at 40 degrees C/75% RH or 12 months at 25 degrees C/65% Relative Humidity (RH). The area under the plasma concentration-time curve, time to peak concentration, and peak plasma concentration were not significantly different between the two tablet formulations investigated in either the fed or fasted states. Pharmacodynamically, no significant differences in SDMT scores between the two formulations were found. In vitro dissolution results predicted in vivo pharmacokinetic and pharmacodynamic results irrespective of formulation or diet used in the controlled release tablet. The controlled release tablets were bioequivalent and pharmacodynamically equivalent irrespective of the tablet formulation.
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43
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Abstract
When barbiturates have been tested in animals trained to discriminate the intravenous benzodiazepine (Bz) anesthetic midazolam, squirrel monkeys and pigeons did not reliably generalize to barbiturates but rats did. To explore this unexpected phenomenon in another species and to extend the midazolam generalization profile to GABAergic compounds not previously tested, five baboons were trained to discriminate midazolam maleate (0.32 mg/kg i.v.) from saline under a two-lever procedure. In tests 10 min after dose delivery, the partial agonist imidazenil, the full agonist chlordiazepoxide, and the receptor-subtype-selective hypnotic zolpidem fully shared discriminative effects with midazolam. The barbiturate pentobarbital did so in only one of five baboons, and the intravenous anesthetic propofol failed to do so in the three baboons tested. Testing 1 min after dose delivery shifted midazolam and zolpidem curves to the left and increased generalization to propofol but not pentobarbital. Taken together with previous published data, partial or full agonism at the Bz binding site appears sufficient for midazolam-like discriminative effects in nonhuman primates, pigeons, and rodents, and modulation through the anesthetic site is sufficient in baboons. However, to date, positive modulation of GABA through the barbiturate site is not generally sufficient for this effect in nonhuman primates and pigeons although it is in rodents.
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Affiliation(s)
- Nancy A Ator
- Department of Psychiatry and Behavioral Sciences, Behavioral Biology Research Center, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Suite 3000, Johns Hopkins Bayview Campus, Baltimore, MD 21224, USA.
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44
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Abstract
Maturation of drug systemic clearance mechanisms during the postnatal period produces dramatic and rapid changes in an infant's capacity to eliminate drugs. A tentative general mathematical model describing the ontogeny of hepatic cytochrome P450 (CYP) enzyme-mediated clearance and renal clearance due to glomerular filtration in the first 6 months of life was elaborated from age-specific in vitro hepatic microsomal activity data (normalised to amount of hepatic microsomal protein) for enzyme-specific probe substrates and in vivo probe substrate data for glomerular filtration (normalised to bodyweight), respectively. The model predicts an age- and clearance pathway-specific Infant Scaling Factor (ISF) for the first 6 months of life. The ISF reflects functional maturation of a specific clearance pathway (normalised to bodyweight) relative to adult values. Therefore, the ISF directly correlates adult clearance values with an infant's capacity to eliminate drugs. Substitution of appropriate model parameter estimates and the age of the infant into the model provides an estimated ISF value, which may then be used to predict the contribution of a particular clearance pathway to total systemic clearance in the infant when adult systemic clearance values are known. The model was tested for its ability to predict infant systemic clearance of drugs whose elimination is principally mediated by a single CYP enzyme or by glomerular filtration. The model performed reasonably well for CYP1A2 and CYP3A4, but poorer predictions were obtained for CYP2D6 and CYP2C because of lack of model complexity and/or inadequate hepatic microsomal activity data to fully describe the maturational process of functional enzyme. For renal clearance due to glomerular filtration, data normalised to bodyweight (kg) showed a limited maturational trend, suggesting that adult renal clearances normalised to bodyweight might reasonably predict infant renal clearances in the first 6 months of life. The model provided reasonable predictions of renal clearance due to glomerular filtration in the infant.
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Affiliation(s)
- Jane Alcorn
- Division of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington 40536, USA
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45
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O'Dwyer PJ, Serpell MG, Millar K, Paterson C, Young D, Hair A, Courtney CA, Horgan P, Kumar S, Walker A, Ford I. Local or general anesthesia for open hernia repair: a randomized trial. Ann Surg 2003; 237:574-9. [PMID: 12677155 PMCID: PMC1514474 DOI: 10.1097/01.sla.0000059992.76731.64] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare patient outcome following repair of a primary groin hernia under local (LA) or general anesthesia (GA) in a randomized clinical trial. SUMMARY BACKGROUND DATA LA hernia repair is thought to be safer for patients, causes less postoperative pain, cost less, and is associated with a more rapid recovery when compared with the same operation performed under GA. METHODS All patients presenting to three surgeons during the study period with a primary groin hernia were considered eligible. Outcome parameters measured including tests of vigilance, divided attention, sustained attention, memory, cognitive function, pain, return to normal activity, and costs. RESULTS Two hundred seventy-nine patients were randomized to LA or GA hernia repair; 276 of these had an operation, with 138 participants in each group. At 6, 24, and 72 hours postoperatively there were no differences in vigilance or divided attention between the groups. Similarly, memory, sustained attention, and cognitive function were not impaired in either group. Although physical activity was significantly impaired at 24 hours, this and return to usual social activities were similar in both groups. While patients in the LA group had significantly less pain on moving, at 6 hours they were less likely to recommend the same operation to someone else. GA hernia repair cost 4% more than the same operation under LA. CONCLUSIONS There are no major differences in patient recovery after LA or GA hernia repair. Patients should be offered a choice of anesthesia, LA or GA, for repair of their groin hernia.
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Affiliation(s)
- Patrick J O'Dwyer
- University Department of Surgery, Western Infirmary and Royal Infirmary, Glasgow G211 6NT, Scotland, UK.
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46
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Monti JM. Benzodiazepines and new non-benzodiazepine agents. Sleep 2003. [DOI: 10.1007/978-1-4615-0217-3_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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47
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Rayburn WF, Christensen HD, Gold KM, Gonzalez CL. Neurobehavior effects in four strains of mice offspring exposed prenatally to alprazolam. Am J Obstet Gynecol 2002; 187:968-72. [PMID: 12388988 DOI: 10.1067/mob.2002.127133] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE This study was performed to determine whether prenatal exposure to alprazolam affects offspring behavior in different strains of mice. STUDY DESIGN Eight to 11 gravid mice of the C3H/He, C57BL/6, A/J, and DBA/2 strains were given either an anxiolytic dose of alprazolam (0.32 mg/kg) or a placebo by gavage on day 18 of an anticipated 19- to 21-day gestation. Neurobehavior tasks were conducted to assess anxiety, learning and memory, and social interaction. Data were analyzed by analysis of variance or a Fisher exact probability test. RESULTS Anxiety in alprazolam-exposed offspring was reduced in C3H/He (P <.05) and A/J (P <.05) newborn infants by separation vocalization but may be increased in the C3H/He adult strain on the plus maze task. Learning was slower among C57BL/6 mice exposed to alprazolam (P <.01), whereas memory was reduced in exposed A/J and DBA/2 offspring (P <.05). Alprazolam exposure was associated with more aggression among C3H/He and C57BL/6 male offspring (P <.01) and with less group activity by C57BL/6 offspring (P <.05). CONCLUSION Altered behaviors in several mouse strains after prenatal exposure to alprazolam suggests a vulnerability of GABA-benozdiazepine receptor formation in fetal brain development.
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Affiliation(s)
- William F Rayburn
- Departments of Obstetrics and Gynecology, University of New Mexico Health Sciences Center, 2211 Lomas Boulevard NE (ACC 4), Albuquerque, NM 87131, USA.
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van Giersbergen PLM, Halabi A, Dingemanse J. Single- and multiple-dose pharmacokinetics of bosentan and its interaction with ketoconazole. Br J Clin Pharmacol 2002; 53:589-95. [PMID: 12047483 PMCID: PMC1874330 DOI: 10.1046/j.1365-2125.2002.01608.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AIMS The present study was conducted to characterize the single- and multiple-dose pharmacokinetics of bosentan, a dual endothelin receptor antagonist, and to investigate a possible pharmacokinetic interaction with ketoconazole. METHODS In a randomized, two-way crossover study, 10 healthy male subjects received treatments A and B. Treatment A consisted of a single dose of 62.5 mg bosentan on day 1 followed by 62.5 mg twice daily for 5.5 days. Treatment B consisted of bosentan (62.5 mg twice daily) for 5.5 days plus concomitant ketoconazole (200 mg once daily) for 6 days. Plasma concentrations of bosentan and its three metabolites were measured on days 1 and 7 of treatment A and on day 6 of treatment B. RESULTS Bosentan was absorbed and eliminated with a tmax of 4.5 h (range 3.5-6.0 h) and a t(1/2) of 5.4 h (95% CI; 4.5, 6.6). Upon multiple dosing, the exposure to bosentan was reduced by 33% without change in tmax and t(1/2). Concomitant administration of ketoconazole increased the Cmax and AUC of bosentan 2.1- (95% CI; 1.5, 2.7) and 2.3-fold (95% CI; 1.8, 2.9), respectively. Exposure to the metabolites was low and represented less than 25% of that to bosentan both after single and multiple doses. In the presence of ketoconazole, formation of the metabolites was inhibited. DISCUSSION The multiple-dose pharmacokinetics of bosentan are consistent with the phenomenon of auto-induction. In the presence of CYP3A4 inhibitors, bosentan concentrations may be increased 2-fold.
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Affiliation(s)
- Paul L M van Giersbergen
- Actelion Pharmaceuticals Ltd, Department of Clinical Pharmacology, Gewerbestrasse 18, 4123 Allschwil, Switzerland.
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49
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Bolon M, Boulieu R, Flamens C, Paulus S, Bastien O. [Sedation induced by midazolam in intensive care: pharmacologic and pharmacokinetic aspects]. ANNALES FRANCAISES D'ANESTHESIE ET DE REANIMATION 2002; 21:478-92. [PMID: 12134593 DOI: 10.1016/s0750-7658(02)00662-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Review on midazolam in order to optimize drug utilisation and therapeutic monitoring. DATA SOURCES Research of English or French articles published until August 2001, using Medline database. The key words were: midazolam, pharmacokinetics, pharmacodynamic, sedation, drug interaction. STUDY SELECTION Original articles, clinical cases and letters to the Editor were selected. Animal studies were excluded. DATA EXTRACTION The articles were analysed according to their interest in midazolam clinical practice. DATA SYNTHESIS Midazolam is a benzodiazepine widely used in intensive care unit, as a sedative, anxiety-relieving, and amnesic drug. Midazolam could be used in patients with cardiac, or respiratory failure, and in neurosurgery. A great interindividual variability on pharmacokinetic and pharmacodynamic response was observed. In intensive care patients, elimination half-life is known to be widely increased. Midazolam is metabolised by hepatic microsomes. The major metabolite is the 1-hydroxymidazolam, which is pharmacologically active. A prolonged sedation due to an accumulation of conjugated metabolite was observed in renal failure patients. Enzymatic inductors or inhibitors could influence pharmacokinetics and pharmacodynamic effects of midazolam. CONCLUSION According to midazolam pharmacokinetic and pharmacodynamic variability, an individual dosage adjustment is essential for long-term sedation. Target controlled sedation could be a mean to limit the variability and to reach quickly the pharmacodynamic effect.
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Affiliation(s)
- M Bolon
- Université Claude Bernard Lyon 1, institut des sciences pharmaceutiques et biologiques, département de pharmacie clinique, de pharmacocinétique et d'évaluation du médicament, 8, avenue Rockefeller, 69373 Lyon, France
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50
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Williams RO, Reynolds TD, Cabelka TD, Sykora MA, Mahaguna V. Investigation of excipient type and level on drug release from controlled release tablets containing HPMC. Pharm Dev Technol 2002; 7:181-93. [PMID: 12066573 DOI: 10.1081/pdt-120003486] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The purpose of this study was to investigate the influence of excipient type and level on the release of alprazolam formulated in controlled release matrix tablets containing hydroxypropyl methylcellulose (HPMC). Each tablet formulation contained alprazolam, HPMC (Methocel K4MP), excipients, and magnesium stearate. The soluble excipients investigated were lactose monohydrate, sucrose, and dextrose, and the insoluble excipients included dicalcium phosphate dihydrate, dicalcium phosphate anhydrous, and calcium sulfate dihydrate. The similarity factor (f2 factor) was used to compare the dissolution profile of each formulation. The insoluble excipients, especially dicalcium phosphate dihydrate, caused the drug to be released at a slower rate and to a lesser extent than the soluble excipients. Soluble excipients created a more permeable hydrated gel layer for drug release, increased the porosity resulting in faster diffusion of drug, and increased the rate of tablet erosion. Use of binary mixtures of lactose monohydrate and dicalcium phosphate dihydrate produced release profiles of intermediate duration. Rapid drug dissolution was obtained when only 9.1% w/w of lactose monohydrate was present in the tablet formulation. Only when the dicalcium phosphate dihydrate level was sufficiently high (36.5% w/w) was the release rate and extent decreased. It was demonstrated that the type and level of excipient influenced the rate and extent of drug release from controlled release tablets containing HPMC. The release mechanism of alprazolam from each tablet formulation was described by either the Hixson-Crowell cube root kinetics equation or Peppas's equation. However, the different excipient types investigated did not influence the release mechanism of alprazolam from the final tablets.
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Affiliation(s)
- Robert O Williams
- College of Pharmacy, Mail Code: A1920, University of Texas at Austin, Austin, TX 78712-1074, USA.
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