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Heneedak HM, Abdelshakour MA, Darwish KM, Mostafa SM, Elgawish MS. Green innovation in analytical chemistry: A sustainable densitometric HPTLC approach for the distinctive separation and quantification of structurally related abused drugs - tramadol, tapentadol, and venlafaxine - in seized pharmaceutical dosage forms. J Pharm Biomed Anal 2024; 243:116109. [PMID: 38518458 DOI: 10.1016/j.jpba.2024.116109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 03/04/2024] [Accepted: 03/14/2024] [Indexed: 03/24/2024]
Abstract
An innovative ecofriendly high-performance thin layer chromatographic (HPTLC) method with spectrophotometric detection for simultaneous determination of Tramadol (TMD), Tapentadol (TAP), and Venlafaxine (VEN) in seized dosage forms was presented. Our method was conducted to achieve separation following the optimal conditions: pre-coated silica gel plates using a green mobile phase (heptane: acetone: ammonia, 7:3:0.5 v/v), with absorbance scanning at 272 nm. The validation of the method was done following International Conference on Harmonization (ICH) guidelines, demonstrates linearity, accuracy, precision, selectivity, robustness, and system suitability. Separation was achieved with a detection limit of 0.34, 0.16, and 0.084 (ug/band) for TMD, TAP, and VEN, respectively, the method successfully analyzes seized samples. Trueness is confirmed through a high degree of similarity between HPTLC and gas chromatography results. The study's ecofriendly approach, simplicity, and selectivity position it as a promising method for efficient, on-site monitoring of seized samples.
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Affiliation(s)
- Hala M Heneedak
- Medicinal Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt; Forensic Chemistry Department, Forensic Medicine Authority, Ministry of Justice, Cairo 11617, Egypt
| | - Mohamed A Abdelshakour
- Pharmaceutical Analytical Chemistry Department, Faculty of pharmacy, Sohag University, Sohag 82524, Egypt
| | - Khaled M Darwish
- Medicinal Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Samia M Mostafa
- Medicinal Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Mohamed Saleh Elgawish
- Medicinal Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt; Chemistry Department, Korea University, Seoul 02841, Republic of Korea.
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McIntyre RS, Agid O, Biesheuvel E, Purushottamahanti P. Effect of venlafaxine on anhedonia and amotivation in patients with major depressive disorder. CNS Spectr 2024; 29:206-214. [PMID: 38685594 DOI: 10.1017/s1092852924000245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
OBJECTIVE Serotonin norepinephrine reuptake inhibitors (SNRIs) have been postulated to afford benefits in alleviating anhedonia and amotivation. This post hoc pooled analysis evaluated the effect of venlafaxine XR, an SNRI, on these symptoms in patients with major depressive disorder (MDD). METHODS Data was pooled from five short-term randomized, placebo-controlled studies of venlafaxine XR for the treatment of MDD, comprising 1087 (venlafaxine XR, n = 585; placebo, n = 502) adult subjects. The change from baseline score in the MADRS anhedonia factor (based on items 1 [apparent sadness], 2 [reported sadness], 6 [concentration difficulties], 7 [lassitude], and 8 [inability to feel]) for anhedonia, and in motivational deficits (based on 3 items of HAM-D17: involvement in work and activities, psychomotor retardation, and energy level [ie, general somatic symptoms]) for amotivation, were measured through 8 weeks. Mixed model repeated measures (MMRMs) were used to analyze changes over time and ANCOVA to analyze the change from baseline at week 8 with LOCF employed to handle missing data. RESULTS At the end of 8 weeks, the change from baseline was significantly greater in patients on venlafaxine XR in both anhedonia (mean, 95% CI: -2.73 [-3.63, -1.82], p < 0.0001) and amotivation scores (mean, 95% CI: -0.78 [-1.04, -0.52], p < 0.0001) than those on placebo. For both measures, the between-group separation from baseline was statistically significant starting from week 2 onwards, and it increased over time. CONCLUSION This analysis demonstrates that venlafaxine XR is effective in improving symptoms of anhedonia and motivational deficits in patients with MDD.
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Affiliation(s)
- Roger S McIntyre
- Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Ofer Agid
- Department of Psychiatry, CAMH and University of Toronto, Toronto, Canada
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Jeong E, Su Y, Li L, Chen Y. Discovering clinical drug-drug interactions with known pharmacokinetics mechanisms using spontaneous reporting systems and electronic health records. J Biomed Inform 2024; 153:104639. [PMID: 38583580 DOI: 10.1016/j.jbi.2024.104639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/17/2024] [Accepted: 04/05/2024] [Indexed: 04/09/2024]
Abstract
OBJECTIVE Although the mechanisms behind pharmacokinetic (PK) drug-drug interactions (DDIs) are well-documented, bridging the gap between this knowledge and clinical evidence of DDIs, especially for serious adverse drug reactions (SADRs), remains challenging. While leveraging the FDA Adverse Event Reporting System (FAERS) database along with disproportionality analysis tends to detect a vast number of DDI signals, this abundance complicates further investigation, such as validation through clinical trials. Our study proposed a framework to efficiently prioritize these signals and assessed their reliability using multi-source Electronic Health Records (EHR) to identify top candidates for further investigation. METHODS We analyzed FAERS data spanning from January 2004 to March 2023, employing four established disproportionality methods: Proportional Reporting Ratio (PRR), Reporting Odds Ratio (ROR), Multi-item Gamma Poisson Shrinker (MGPS), and Bayesian Confidence Propagating Neural Network (BCPNN). Building upon these models, we developed four ranking models to prioritize DDI-SADR signals and cross-referenced signals with DrugBank. To validate the top-ranked signals, we employed longitudinal EHRs from Vanderbilt University Medical Center and the All of Us research program. The performance of each model was assessed by counting how many of the top-ranked signals were confirmed by EHRs and calculating the average ranking of these confirmed signals. RESULTS Out of 189 DDI-SADR signals identified by all four disproportionality methods, only two were documented in the DrugBank database. By prioritizing the top 20 signals as determined by each of the four disproportionality methods and our four ranking models, 58 unique DDI-SADR signals were selected for EHR validations. Of these, five signals were confirmed. The ranking model, which integrated the MGPS and BCPNN, demonstrated superior performance by assigning the highest priority to those five EHR-confirmed signals. CONCLUSION The fusion of disproportionality analysis with ranking models, validated through multi-source EHRs, presents a groundbreaking approach to pharmacovigilance. Our study's confirmation of five significant DDI-SADRs, previously unrecorded in the DrugBank database, highlights the essential role of advanced data analysis techniques in identifying ADRs.
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Affiliation(s)
- Eugene Jeong
- Department of Biomedical Informatics, School of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Yu Su
- Department of Computer Science and Engineering, College of Engineering, The Ohio State University, Columbus, OH, United States
| | - Lang Li
- Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, OH, United States
| | - You Chen
- Department of Biomedical Informatics, School of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States; Department of Computer Science, School of Engineering, Vanderbilt University, Nashville, TN, United States.
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Korkmaz SA, Guney T, Dilek I, Caykoylu A. Interactions between Antidepressants and Warfarin: A Review. CURRENT PSYCHIATRY RESEARCH AND REVIEWS 2021. [DOI: 10.2174/2666082216999200622135657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Since warfarin has a very narrow therapeutic index, the interaction between
warfarin and antidepressants is very critical and has potentially severe consequences. It is unclear
whether clinicians have sufficient knowledge about the risk of bleeding when warfarin and antidepressants
are used concomitantly.
Objective:
In this systematic review, we discuss the main considerations when using warfarin with
antidepressants.
Methods:
The information about warfarin-antidepressant interactions was obtained from Google
Scholar®, PubMed/MEDLINE® and a hand search of the published literature. The following research
terms which were systematically combined with each other to find articles: warfarin, anticoagulant,
interactions, antidepressant (and each antidepressant name individually), SSRI, SNRI, TCA, MAOI.
Results:
Several possible mechanisms that can cause bleeding when antidepressants and warfarin
are used concomitantly, have been discussed. According to the available data, sertraline and citalopram/
escitalopram are safer antidepressants to use with warfarin, whereas fluoxetine and fluvoxamine
have a higher interaction potential with warfarin. The remaining antidepressants appear to lie
somewhere in between and have little empirical data to guide the clinicians.
Conclusion:
It is recommended that when an antidepressant is prescribed to a patient using warfarin,
patient’s international normalized ratio (INR) level should be checked regularly. In this review,
the interaction between warfarin and antidepressants, including new ones, were evaluated
inclusively and in detail.
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Affiliation(s)
| | - Tekin Guney
- Department of Hematology, University of Health Sciences Affiliated with of Ankara City Hospital, Ankara, Turkey
| | - Imdat Dilek
- Department of Hematology, Faculty of Medicine, Yildirim Beyazit University Affiliated with of Ankara City Hospital, Ankara, Turkey
| | - Ali Caykoylu
- Department of Psychiatry, Faculty of Medicine, Yildirim Beyazit University, Ankara, Turkey
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Abstract
There is increasing recognition that epilepsy can be associated with a broad spectrum of comorbidities. While epileptic seizures are an essential element of epilepsy in children, there is a spectrum of neurological, mental health and cognitive disorders that add to the disease burden of childhood epilepsy resulting in a decreased quality of life. The most common comorbid conditions in childhood epilepsy include depression, anxiety, autism spectrum disorders, sleep disorders, attention deficits, cognitive impairment, and migraine. While epilepsy can result in comorbidities, many of the comorbidities of childhood have a bi-directional association, with the comorbid condition increasing risk for epilepsy and epilepsy increasing the risk for the comorbid condition. The bidirectional feature of epilepsy and the comorbidities suggest a common underlying pathological basis for both the seizures and comorbid condition. While recognition of the comorbid conditions of pediatric epilepsies is increasing, there has been a lag in the development of effective therapies partly out of concern that drugs used to treat the comorbid conditions could increase seizure susceptibility. There is now some evidence that most drugs used for comorbid conditions are safe and do not lower seizure threshold. Unfortunately, the evidence showing drugs are effective in treating many of the childhood comorbidities of epilepsy is quite limited. There is a great need for randomized, placebo-controlled drug trials for efficacy and safety in the treatment of comorbidities of childhood epilepsy.
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Affiliation(s)
- Gregory L Holmes
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Stafford Hall, 118C, Burlington, VT, 05405, USA.
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Azizi M, Elyasi F, Niksolat Roodposhti F. Bradycardia caused by interaction of venlafaxine and cyclosporine: A case report. CASPIAN JOURNAL OF INTERNAL MEDICINE 2019; 10:463-467. [PMID: 31814947 PMCID: PMC6856918 DOI: 10.22088/cjim.10.4.463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Background: Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are prescribed widely for the treatment of depression, anxiety disorders and other psychiatric disorders. Although antidepressants are considered as a safety drug category but unexpected cardiovascular events have been reported as the most serious complications. The aim of this study was to introduce a case presentation on bradycardia due to the drug interference of venlafaxine and cyclosporine. Case presentation: The patient was a 38-year old woman diagnosed with systemic lupus erythematosus 5 years ago, who was admitted to a general educational hospital in northern Iran due to intensified rheumatologic symptoms and complaining about abdominal pain. Cyclosporine tab were administered to the patient, 50 mg twice daily. Two weeks after the administration of cyclosporine, the level of blood cyclosporine was checked. The patient became bradycardic after starting a single dose of venlafaxine (heart rate 52 ppm). Cardiac assessment showed no reason for bradycardia and it subsided after a drop of venlafaxine. Conclusion: As a result of the potential adverse drug interactions between cyclosporine and antidepressants such as venlafaxine, physicians should be aware of the possibility of bradycardia in the simultaneous prescription of these drugs in cases.
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Affiliation(s)
- Marzieh Azizi
- Sexual and Reproductive Health Research Center, Nasibeh Nursing and Midwifery Faculty, Mazandaran University of Medical Sciences, Sari, Iran
| | - Forouzan Elyasi
- Department of Psychiatry, Psychiatry and Behavioral Sciences Research Center and addiction Institute, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Fatemeh Niksolat Roodposhti
- Department of Internal Medicine, Orthopedic Research Center, Mazandaran University of Medical Sciences, Sari, Iran
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Hua L, Chiang C, Cong W, Li J, Wang X, Cheng L, Feng W, Quinney SK, Wang L, Li L. The Cancer Drug Fraction of Metabolism Database. CPT Pharmacometrics Syst Pharmacol 2019; 8:511-519. [PMID: 31206254 PMCID: PMC6656935 DOI: 10.1002/psp4.12417] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 03/29/2019] [Indexed: 02/06/2023] Open
Abstract
This study aims to create a database for quantifying the fraction of metabolism of cytochrome P450 isozymes for cancer drugs approved by the US Food and Drug Administration. A reproducible data collection protocol was developed to extract essential information, including both substrate-depletion and metabolite-formation data from publicly available in vitro selective cytochrome P450 enzyme inhibition studies. We estimated the fraction of metabolism from the curated data. To demonstrate the utility of this database, we conducted an in vitro drug interaction prediction for the 42 cancer drugs. In the drug-drug interaction prediction, we identified 31 drug pairs with at least one cancer drug in each pair that had predicted area under concentration ratios > 2. We further found clinical drug interaction pieces of evidence in the literature to support 20 of these 31 drug-drug interaction pairs.
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Affiliation(s)
- Liyan Hua
- College of AutomationHarbin Engineering UniversityHarbinChina
| | - Chien‐Wei Chiang
- Department of Biomedical InformaticsCollege of MedicineThe Ohio State UniversityColumbusOhioUSA
| | - Wang Cong
- College of AutomationHarbin Engineering UniversityHarbinChina
| | - Jin Li
- College of AutomationHarbin Engineering UniversityHarbinChina
| | - Xueying Wang
- College of AutomationHarbin Engineering UniversityHarbinChina
| | - Lijun Cheng
- Department of Biomedical InformaticsCollege of MedicineThe Ohio State UniversityColumbusOhioUSA
| | - Weixing Feng
- College of AutomationHarbin Engineering UniversityHarbinChina
| | - Sara K. Quinney
- The Center for Computational Biology and BioinformaticsSchool of MedicineIndiana UniversityIndianapolisIndianaUSA
- Department of Obstetrics and GynecologySchool of MedicineIndiana UniversityIndianapolisIndianaUSA
| | - Lei Wang
- College of AutomationHarbin Engineering UniversityHarbinChina
- Department of Biomedical InformaticsCollege of MedicineThe Ohio State UniversityColumbusOhioUSA
| | - Lang Li
- Department of Biomedical InformaticsCollege of MedicineThe Ohio State UniversityColumbusOhioUSA
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Lin HP, Sun D, Zhang X, Wen H. Physiologically Based Pharmacokinetic Modeling for Substitutability Analysis of Venlafaxine Hydrochloride Extended-Release Formulations Using Different Release Mechanisms: Osmotic Pump Versus Openable Matrix. J Pharm Sci 2016; 105:3088-3096. [DOI: 10.1016/j.xphs.2016.06.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 11/28/2022]
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Yang Y, Gao X, Xu Y. The dilemma of treatments for epileptic patients with depression. Int J Neurosci 2014; 125:566-77. [PMID: 25271800 DOI: 10.3109/00207454.2014.959122] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Depression is a state of low mood and aversion to activity. It may occur due to existence of other mental or physical diseases or from the medications for those illnesses. It is one of the leading sources of disability. Among these physical diseases, epilepsy is widely recognized as one of the main causes of depression. Patients with epilepsy are at high risk of developing depressive symptoms, and the suicide rates in patients with epilepsy have been reported to be much higher than in the general population. However, due to fears of lowering seizure threshold and adverse drug interactions between antidepressants and antiepileptic drugs, physician are reluctant to place patients with epilepsy on antidepressant medication. As a result, the question has been raised that what the best managements should be used to treat epileptic patients with depression. In this review, the currently used medications for antidepressants and antiepileptic drugs were summarized by their working targets in order to establish appropriate pharmacological management of depression and epilepsy. Despite the complex relationship between epilepsy and depression, coadministration of antidepressants and AEDs can still be done safely and effectively under the conditions of good clinical management. The ideal antidepressants for people with epilepsy should be efficacious but with few adverse effects, which will not antagonize GABAergic mechanisms or interfere with plasma anticonvulsant concentrations.
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Affiliation(s)
- Yang Yang
- 1Department of Clinical Psychology, Subei People Hospital of Jiangsu Province, Yangzhou, 225001, China
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Unterecker S, Riederer P, Proft F, Maloney J, Deckert J, Pfuhlmann B. Effects of gender and age on serum concentrations of antidepressants under naturalistic conditions. J Neural Transm (Vienna) 2012; 120:1237-46. [PMID: 23254926 DOI: 10.1007/s00702-012-0952-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 12/04/2012] [Indexed: 11/27/2022]
Abstract
Therapeutic drug monitoring (TDM) data of antidepressant drugs are often evaluated using homogeneous samples of selected individuals without psychiatric or somatic comorbidity. These data may have limitations in transferability to everyday clinical practice. Hence, studies under naturalistic conditions are important to clarify the full clinical relevance of TDM of antidepressants. TDM analyses were retrospectively evaluated for a 3-year period from 2008 to 2010. The influence of gender and age on dose-corrected serum concentrations of antidepressants was examined in a standard clinical setting. 693 TDM analyses of amitriptyline and nortriptyline (AMI + NOR), 160 of citalopram (CIT), 152 of clomipramine and N-clomipramine (CLO + N-CLO), 272 of doxepine and N-doxepine (DOX + N-DOX), 359 of escitalopram (ESC), 198 of fluoxetine and N-fluoxetine (FLU + N-FLU), 92 of maprotiline (MAP), 888 of mirtazapine (MIR), and 77 of sertraline (SER) remained in the sample. Females had significantly higher dose-corrected serum concentrations of AMI + NOR (32 %), CIT (29 %), DOX + N-DOX (29 %), and MIR (20 %), and patients older than 60 years had significantly higher dose-corrected serum concentrations of AMI + NOR (21 %), CIT (40 %), DOX + N-DOX (48 %), MAP (46 %), MIR (24 %), and SER (67 %). Comparing the two extreme groups, females >60 years showed a remarkably higher dose-corrected serum concentration of AMI + NOR (52 %), CIT (78 %), DOX + N-DOX (86 %), and MIR (41 %) in contrast to males ≤60 years. Gender and age have a significant influence on the serum concentrations of different antidepressant drugs, and additive effects must be considered. TDM is recommended to reduce the risk of adverse effects due to supratherapeutic serum levels, also in a naturalistic clinical setting.
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Affiliation(s)
- S Unterecker
- Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital of Würzburg, Füchsleinstrasse 15, 97080, Würzburg, Germany.
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Bhuiyan M, Petropoulos S, Gibb W, Matthews SG. Sertraline alters multidrug resistance phosphoglycoprotein activity in the mouse placenta and fetal blood-brain barrier. Reprod Sci 2012; 19:407-15. [PMID: 22510699 DOI: 10.1177/1933719111424438] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Phosphoglycoprotein (P-gp) is highly expressed in the placental syncytiotrophoblast and prevents xenobiotics from entering the fetus. In tumor cells, P-gp-mediated substrate efflux is inhibited by selective serotonin reuptake inhibitors (SSRIs). However, nothing is known regarding the effects of SSRIs on P-gp function in the placenta or fetal tissues. We hypothesized that the SSRI sertraline would decrease P-gp-mediated drug efflux at the placenta and fetal blood-brain barrier (BBB)-increasing P-gp substrate transfer from the mother to the fetus and fetal brain. In contrast to our hypothesis, this study presents the novel findings that sertraline (4 hours exposure) increases placental P-gp-mediated efflux (P < .001), resulting in decreased drug transfer to the fetus. Meanwhile, sertraline decreases fetal (P < .001) and maternal (P < .05) BBB P-gp-mediated efflux, resulting in increased drug transfer into the fetal and maternal brain from the circulation. This suggests that P-gp regulation by sertraline is tissue specific. These findings have important clinical implications with respect to fetal protection during maternal drug therapy in pregnancy.
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Affiliation(s)
- Manzerul Bhuiyan
- Department of Physiology, University of Toronto, Toronto, Canada
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Kingbäck M, Karlsson L, Zackrisson AL, Carlsson B, Josefsson M, Bengtsson F, Ahlner J, Kugelberg FC. Influence of CYP2D6 genotype on the disposition of the enantiomers of venlafaxine and its major metabolites in postmortem femoral blood. Forensic Sci Int 2011; 214:124-34. [PMID: 21840145 DOI: 10.1016/j.forsciint.2011.07.034] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 07/05/2011] [Accepted: 07/18/2011] [Indexed: 11/18/2022]
Abstract
Venlafaxine (VEN) is an antidepressant drug mainly metabolized by the cytochrome P450 (CYP) enzyme CYP2D6 to the active metabolite O-desmethylvenlafaxine (ODV). VEN is also metabolized to N-desmetylvenlafaxine (NDV) via CYP3A4. ODV and NDV are further metabolized to N,O-didesmethylvenlafaxine (DDV). VEN is a racemic mixture of the S- and R-enantiomers and these have in vitro displayed different degrees of serotonin and noradrenaline reuptake inhibition. The aim of the study was to investigate if an enantioselective analysis of VEN and its metabolites, in combination with genotyping for CYP2D6, could assist in the interpretation of forensic toxicological results in cases with different causes of deaths. Concentrations of the enantiomers of VEN and metabolites were determined in femoral blood obtained from 56 autopsy cases with different causes of death. The drug analysis was done by liquid chromatography tandem mass spectrometry (LC/MS/MS) and the CYP2D6 genotyping by PCR and pyrosequencing. The mean (median) enantiomeric S/R ratios of VEN, ODV, NDV and DDV were 0.99 (0.91), 2.17 (0.93), 0.92 (0.86) and 1.08 (1.03), respectively. However, a substantial variation in the relationship between the S- and R-enantiomers of VEN and metabolites was evident (S/R ratios ranging from 0.23 to 17.6). In six cases, a low S/R VEN ratio (mean 0.5) was associated with a high S/R ODV ratio (mean 11.9). Genotyping showed that these individuals carried two inactive CYP2D6 genes indicating a poor metabolizer phenotype. From these data we conclude that enantioselective analysis of VEN and ODV can predict if a person is a poor metabolizer genotype/phenotype for CYP2D6. Knowledge of the relationship between the S- and R-enantiomers of this antidepressant drug and its active metabolite is also important since the enantiomers display different pharmacodynamic profiles.
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Affiliation(s)
- Maria Kingbäck
- Division of Drug Research, Clinical Pharmacology, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
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Abstract
Objectives: To compare the efficacy and pharmacologic, pharmacokinetic, drug interaction and adverse effect profiles of duloxetine and venlafaxine. Methods: A systematic review of the literature pertaining to duloxetine and venlafaxine was conducted using a computer-aided search of MEDLINE and EMBASE for the period January 1988 to May 2008 with the following search terms: venlafaxine and duloxetine and depression, clinical studies, pharmacology, drug interactions, pharmacokinetics, adverse effects, safety, case reports and review articles. Results: Duloxetine and venlafaxine have comparable efficacy and share similar pharmacologic profiles but differ somewhat in their pharmacokinetic profiles, drug interactions and adverse effects. Both agents block the reuptake of serotonin and norepinephrine and both are substrates for the cytochrome P450 2D6 isoenzyme; however, duloxetine inhibits these enzymes to a moderate extent, whereas venlafaxine is only a weak inhibitor. Furthermore, duloxetine is more extensively bound to protein than venlafaxine. Venlafaxine is more likely to elevate blood pressure in a dose-related manner. Both duloxetine and venlafaxine have the potential to cause hepatic injury. Conclusions: Although venlafaxine and duloxetine have similar efficacy in the treatment of depression, differences in their adverse effects and pharmacokinetic profiles suggest that one agent may be preferred over the other in certain patient groups.
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Affiliation(s)
- Sylvia Zerjav
- British Columbia Mental Health and Addictions Services, Coquitlam (Zerjav); the Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver (Zerjav); the Fraser Health Authority, Vancouver (Tse); and the Department of Psychiatry, Prince George Regional Hospital, Prince George (Scott), British Columbia. Contact
| | - Gordon Tse
- British Columbia Mental Health and Addictions Services, Coquitlam (Zerjav); the Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver (Zerjav); the Fraser Health Authority, Vancouver (Tse); and the Department of Psychiatry, Prince George Regional Hospital, Prince George (Scott), British Columbia. Contact
| | - Michael J.W. Scott
- British Columbia Mental Health and Addictions Services, Coquitlam (Zerjav); the Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver (Zerjav); the Fraser Health Authority, Vancouver (Tse); and the Department of Psychiatry, Prince George Regional Hospital, Prince George (Scott), British Columbia. Contact
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Gareri P, De Fazio P, Russo E, Marigliano N, De Fazio S, De Sarro G. The safety of clozapine in the elderly. Expert Opin Drug Saf 2008; 7:525-38. [PMID: 18759705 DOI: 10.1517/14740338.7.5.525] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Clozapine was the first atypical 'broad spectrum' antipsychotic drug to be marketed and the first agent approved for the treatment of schizophrenia refractory to other medications. It is also effective for the treatment of aggressive behaviour in schizophrenic and demented patients and in the management of psychosis and aggression in Parkinson's disease and Lewy body dementia. OBJECTIVE The aim of this review is to study the safety of clozapine for use in elderly patients. METHODS An extensive Medline search was made. Some studies that were referenced in reports from our pharmacovigilance centre and from regulatory agencies such as the FDA, EMEA and WHO were included. CONCLUSIONS Clozapine treatment in the elderly requires a careful geriatric assessment. However, its use is strongly limited by the possibility of onset of severe adverse effects such as potentially fatal agranulocytosis, myocarditis and others such as seizures, weight gain and metabolic adverse effects.
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Affiliation(s)
- Pietro Gareri
- University "Magna Graecia" of Catanzaro, "Mater Domini" University Hospital, Clinical Pharmacology and Pharmacovigilance Unit, Faculty of Medicine and Surgery, Department of Experimental and Clinical Medicine, Catanzaro, Italy.
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Mandrioli R, Mercolini L, Cesta R, Fanali S, Amore M, Raggi MA. Analysis of the second generation antidepressant venlafaxine and its main active metabolite O-desmethylvenlafaxine in human plasma by HPLC with spectrofluorimetric detection. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 856:88-94. [PMID: 17581798 DOI: 10.1016/j.jchromb.2007.05.046] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 03/08/2007] [Accepted: 05/21/2007] [Indexed: 10/23/2022]
Abstract
A high-performance liquid chromatographic method has been developed for the determination of the recent serotonin and norepinephrine reuptake inhibitor (SNRI) venlafaxine and its main active metabolite, O-desmethylvenlafaxine, in human plasma. Separation was obtained by using a reversed-phase column (C8, 150 x 4.6 mm I.D., 5 microm) and a mobile phase composed of 75% aqueous phosphate buffer containing triethylamine at pH 6.8 and 25% acetonitrile. Fluorescence detection was used, exciting at lambda=238 nm and monitoring the emission at lambda=300 nm. Citalopram was used as the internal standard. A careful pre-treatment of plasma samples was developed, using solid-phase extraction with C1 cartridges (100 mg, 1 mL). The limit of quantification (LOQ) was 1.0 ng mL(-1) and the limit of detection (LOD) was 0.3 ng mL(-1) for both analytes. The method was applied with success to plasma samples taken from patients undergoing treatment with venlafaxine. Precision data, as well as accuracy results, were satisfactory and no interference from other drugs was found. Hence, the method is suitable for therapeutic drug monitoring of venlafaxine and its main metabolite in depressed patients' plasma.
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Affiliation(s)
- Roberto Mandrioli
- Pharmaco-Toxicological Analysis Laboratory, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Alma Mater Studiorum, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
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17
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Brandt C, Pohlmann-Eden B. Interaktionen zwischen Antiepileptika und Psychopharmaka. ZEITSCHRIFT FÜR EPILEPTOLOGIE 2006. [DOI: 10.1007/s10309-006-0185-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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18
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Stahl SM, Grady MM, Moret C, Briley M. SNRIs: their pharmacology, clinical efficacy, and tolerability in comparison with other classes of antidepressants. CNS Spectr 2005; 10:732-47. [PMID: 16142213 DOI: 10.1017/s1092852900019726] [Citation(s) in RCA: 309] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The class of serotonin and norepinephrine reuptake inhibitors (SNRIs) now comprises three medications: venlafaxine, milnacipran, and duloxetine. These drugs block the reuptake of both serotonin (5-HT) and norepinephrine with differing selectivity. Whereas milnacipran blocks 5-HT and norepinephrine reuptake with equal affinity, duloxetine has a 10-fold selectivity for 5-HT and venlafaxine a 30-fold selectivity for 5-HT. All three SNRIs are efficacious in treating a variety of anxiety disorders. There is no evidence for major differences between SNRIs and SSRIs in their efficacy in treating anxiety disorders. In contrast to SSRIs, which are generally ineffective in treating chronic pain, all three SNRIs seem to be helpful in relieving chronic pain associated with and independent of depression. Tolerability of an SNRI at therapeutic doses varies within the class. Although no direct comparative data are available, venlafaxine seems to be the least well-tolerated, combining serotonergic adverse effects (nausea, sexual dysfunction, withdrawal problems) with a dose-dependent cardiovascular phenomenon, principally hypertension. Duloxetine and milnacipran appear better tolerated and essentially devoid of cardiovascular toxicity.
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Affiliation(s)
- Stephen M Stahl
- Department of Psychiatry, University of California, San Diego, San Diego, CA, USA
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19
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Abstract
OBJECTIVE To describe the concepts of both pharmacokinetics and pharmacodynamics and how it applies to palliative medicine. DATA SOURCES Research and review articles and textbooks. CONCLUSION Most patients who have an illness that requires palliation are elderly, have co-morbid conditions, and are on many medications. Both age and disease can alter the way drugs are handled by the body (pharmacokinetics) and how they affect the body (pharmacodynamics). IMPLICATIONS FOR NURSING PRACTICE The oncology nurse, armed with the correct knowledge about medications, can have an important inmpact on improving the patient's care, safety, and quality of life.
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Zullino DF, Cucchia G. Mydriasis, Hypertension, and Tachycardia Possibly Associated with Venlafaxine Augmentation of Mirtazapine. J Pharm Technol 2004. [DOI: 10.1177/875512250402000605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective: To report a case of mydriasis and hypertension resulting from concomitant use of mirtazapine and venlafaxine. Case Summary: A 36-year-old man had been treated for 7 weeks with mirtazapine up to 60 mg/day without satisfactory therapeutic effects. Venlafaxine extended-release up to 150 mg/day was added with the aim to boost the antidepressant effect. After 5 days of venlafaxine treatment, the patient developed apparent mydriasis, and after 9 days of therapy, the patient's blood pressure peaked at 200/120 mm Hg. While he remained under mirtazapine therapy, both symptoms resolved within 24 hours after venlafaxine discontinuation. Discussion: A rise in blood pressure is a well-known phenomenon with venlafaxine. As of September 27, 2004, this is the first case of hypertension after venlafaxine augmentation of mirtazapine and the first case to report a preceding mydriasis. We propose an excess of noradrenergic activity due to the combination of venlafaxine and mirtazapine to be the most probable cause. Conclusions: Whereas the mirtazapine/venlafaxine combination seems a promising approach in the treatment of refractory depression, this strategy may be associated with adverse drug events not observed with either of the drugs when given alone. Mydriasis may be a good premonitory sign for hypertension.
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Affiliation(s)
- Daniele F Zullino
- DANIELE F ZULLINO MD, Clinical Associate, University Department of Adult Psychiatry, Prilly—Lausanne, Switzerland
| | - Gianni Cucchia
- GIANNI CUCCHIA MD, Consultant, University Department of Adult Psychiatry, Prilly—Lausanne
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Angulo J, Cuevas P, Cuevas B, Gupta S, Sáenz de Tejada I. Mechanisms for the Inhibition of Genital Vascular Responses by Antidepressants in a Female Rabbit Model. J Pharmacol Exp Ther 2004; 310:141-9. [PMID: 15034084 DOI: 10.1124/jpet.103.063362] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Vaginal and clitoral vasodilator responses (genital vascular responses; GVRs) to pelvic nerve electrical stimulation in female rabbits were measured by laser Doppler flow needle probes. The intravenous administration of various treatments was evaluated. GVRs were attenuated by a nitric-oxide synthase inhibitor (48.5 and 51.8% of control at 8 Hz in the vagina and clitoris, respectively) and norepinephrine (NE) (78.5 and 61.5%), whereas serotonin (5-HT) had no inhibitory effect. The selective 5-HT reuptake inhibitor (SSRI) escitalopram did not modify GVRs, whereas the SSRI paroxetine dose-dependently inhibited GVRs in female rabbits (43.3 and 53.1% at 5 mg/kg). GVRs were also significantly inhibited by the 5-HT and NE reuptake inhibitors venlafaxine (53.4 and 52.6% at 5 mg/kg) and duloxetine (40.9 and 37.4% at 1 mg/kg). L-arginine prevented the inhibitory effects of paroxetine (105.5 and 115.3%) and partially prevented duloxetine-induced reduction of GVRs but had no effect on the inhibition of GVRs induced by venlafaxine. Conversely, the alpha-adrenergic receptor blocker phentolamine had no effect on paroxetine-induced reduction of GVRs, partially prevented the inhibitory effects of duloxetine, and fully prevented the effects of venlafaxine (93.0 and 96.7%). Duloxetine-induced inhibition of GVRs was completely prevented by combined administration of L-arginine and phentolamine (123.5 and 103.6%). Although 5-HT or the highly selective SRI escitalopram did not inhibit GVRs, NE or inhibition of nitric oxide (NO) synthesis did. Inhibition of the NO pathway by paroxetine and duloxetine or activation of alpha-adrenergic mechanisms by venlafaxine and duloxetine lead to antidepressant-induced inhibition of GVRs in female rabbits.
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Affiliation(s)
- Javier Angulo
- Fundación para la Investigación y el Desarrollo en Andrología, Madrid, Spain
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22
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Abstract
New psychotropic drugs introduced in clinical practice in recent years include new antidepressants, such as selective serotonin reuptake inhibitors (SSRI) and 'third generation' antidepressants, and atypical antipsychotics, i.e. clozapine, risperidone, olanzapine, quetiapine, ziprasidone and amisulpride. These agents are extensively metabolized in the liver by cytochrome P450 (CYP) enzymes and are therefore susceptible to metabolically based drug interactions with other psychotropic medications or with compounds used for the treatment of concomitant somatic illnesses. New antidepressants differ in their potential for metabolic drug interactions. Fluoxetine and paroxetine are potent inhibitors of CYP2D6, fluvoxamine markedly inhibits CYP1A2 and CYP2C19, while nefazodone is a potent inhibitor of CYP3A4. These antidepressants may be involved in clinically significant interactions when coadministered with substrates of these isoforms, especially those with a narrow therapeutic index. Other new antidepressants including sertraline, citalopram, venlafaxine, mirtazapine and reboxetine are weak in vitro inhibitors of the different CYP isoforms and appear to have less propensity for important metabolic interactions. The new atypical antipsychotics do not affect significantly the activity of CYP isoenzymes and are not expected to impair the elimination of other medications. Conversely, coadministration of inhibitors or inducers of the CYP isoenzymes involved in metabolism of the various antipsychotic compounds may alter their plasma concentrations, possibly leading to clinically significant effects. The potential for metabolically based drug interactions of any new psychotropic agent may be anticipated on the basis of knowledge about the CYP enzymes responsible for its metabolism and about its effect on the activity of these enzymes. This information is essential for rational prescribing and may guide selection of an appropriate compound which is less likely to interact with already taken medication(s).
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Affiliation(s)
- Edoardo Spina
- Department of Clinical and Experimental Medicine and Pharmacology, Section of Pharmacology, University of Messina, Policlinico Universitario, Via Consolare Valeria, 98125 Messina, Italy.
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23
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Connor H. Serotonin syndrome after single doses of co-amoxiclav during treatment with venlafaxine. J R Soc Med 2003. [PMID: 12724434 PMCID: PMC539477 DOI: 10.1258/jrsm.96.5.233] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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Connor H. Serotonin Syndrome after Single Doses of Co-Amoxiclav during Treatment with Venlafaxine. Med Chir Trans 2003; 96:233-4. [PMID: 12724434 PMCID: PMC539477 DOI: 10.1177/014107680309600508] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Gex-Fabry M, Balant-Gorgia AE, Balant LP. Therapeutic drug monitoring of olanzapine: the combined effect of age, gender, smoking, and comedication. Ther Drug Monit 2003; 25:46-53. [PMID: 12548144 DOI: 10.1097/00007691-200302000-00007] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Therapeutic drug monitoring (TDM) data for the antipsychotic drug olanzapine were investigated with respect to concentration versus dose relationship, intraindividual versus interindividual variability, and the combined influence of patient characteristics on steady-state concentration. The study included 250 patients, with daily doses ranging from 2.5 to 30 mg. Median concentration to dose ratio was 2.1 (ng/mL)/(mg/d), with 90% of the distribution in a fivefold range. In the first subgroup of patients with two measurements at different doses (n = 21), data were in keeping with linear concentration versus dose relationship. In the second subgroup of patients with repeated measurements at a constant daily dose (n = 40), estimates of within-patient and between-patient variabilities were 30.5% and 49.4%, respectively. In the whole sample, multiple regression analysis of dose-normalized concentration revealed significant effects of time postdose (-18% per 12 hours delay, P < 0.05), age >/=60 years (+27%, P < 0.005), cigarette smoking (-12%, P < 0.05), and comedication with fluvoxamine (+74%, P < 0.001), paroxetine, fluoxetine, or sertraline (considered together, +32%, P < 0.05), venlafaxine (+27%, P < 0.05), and inducers of P450 enzymes (-40%, P < 0.001). The final model included a tendency for higher concentration associated with female gender (+11%, P = 0.07) and accounted for 27% of observed interindividual variability. When considering a worst-case scenario, an elderly, nonsmoking woman prescribed fluvoxamine comedication was predicted to reach a 4.6-fold higher olanzapine concentration than a young male smoker coadministered carbamazepine. The current study suggests that patients characterized by a combination of factors associated with altered metabolism may benefit from olanzapine TDM.
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26
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Gastó C, Navarro V, Marcos T, Portella MJ, Torra M, Rodamilans M. Single-blind comparison of venlafaxine and nortriptyline in elderly major depression. J Clin Psychopharmacol 2003; 23:21-6. [PMID: 12544371 DOI: 10.1097/00004714-200302000-00004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The objective of this single-blind study was to compare the efficacy and safety of venlafaxine extended-release and nortriptyline in elderly patients with moderate to severe major depression. In- and out-patients (N=68) with unipolar major depression were randomized to receive 6-month treatment with either nortriptyline or venlafaxine. Outcomes of the two groups were compared using measures including the Hamilton Depression Rating Scale (HDRS) and the Newcastle Scale. Side effects were assessed with the UKU side-effect rating scale. Of the 34 venlafaxine-treated patients, 22 were remitters, 7 were nonremitters, and 5 dropped out. The intent-to-treat remission rate was 71% (22 of 31). Of the 34 who received nortriptyline, 21 were remitters, 7 were nonremitters, and 6 dropped out. The intent-to-treat remission rate was 70% (21 of 30). These results suggest that the remission rate with a therapeutic plasma level of nortriptyline is similar to the remission rate with a standard dose of venlafaxine in this group of elderly major depressed patients. No significant differences were observed between dropout rates in the two groups, but autonomic side-effects were significantly more frequent for nortriptyline than for venlafaxine. These results confirm the efficacy and safety of venlafaxine extended-release for treating elderly major depression.
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Affiliation(s)
- Cristóbal Gastó
- Clinical Institute of Psychiatry and Psychology and Toxicology Unit, Hospital Clínic, University of Barcelona (UB), Spain
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27
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Gareri P, De Fazio P, Stilo M, Ferreri G, De Sarro G. Conventional and Atypical Antipsychotics in the Elderly. Clin Drug Investig 2003; 23:287-322. [PMID: 17535043 DOI: 10.2165/00044011-200323050-00001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Psychoses are major mental disorders marked by derangement of personality and loss of contact with reality, and are common in the elderly. Various hypotheses suggest the pivotal role of abnormal neurotransmitter and neuropeptide systems in psychotic patients, the most studied of which are the dopaminergic, serotonergic and glutamatergic systems. In particular, long-term treatment with antagonists at dopamine (D) and serotonin (5-hydroxytryptamine; 5-HT) receptors and agonists at glutamate receptors may improve symptoms. Treatment with antipsychotics is very common in the elderly and often indispensable. However, for successful treatment it is essential to have an adequate multidimensional assessment of the geriatric patient and of his or her polypathology and polypharmacy, together with knowledge of age-dependent pharmacokinetics and pharmacodynamic changes and drug-drug interactions.Conventional antipsychotics such as haloperidol, chlorpromazine, promazine, tiapride and zuclopenthixol are D(2)-receptor antagonists and inhibit dopaminergic neurotransmission in a dose-related manner. They decrease the intensity of all psychotic symptoms, although not necessarily to the same extent and with the same time course. Negative symptoms may persist to a much more striking extent than delusions, hallucinations and thought disorders, and there is a dose-related incidence of extrapyramidal side effects (EPS). Newer antipsychotics, such as clozapine, olanzapine, risperidone, quetiapine and ziprasidone, have a different receptor-binding profile, interacting with both D and 5-HT receptors; they less frequently cause EPS and are better tolerated in the elderly. Their use is advantageous because they are effective both on positive and negative symptoms of schizophrenia and may also be used in the treatment of behavioural disturbances in elderly and/or demented individuals. The use of clozapine is limited by the onset of agranulocytosis, whereas olanzapine, risperidone, quetiapine and, more recently, ziprasidone are widely used, with good results in the above-mentioned diseases.
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Affiliation(s)
- Pietro Gareri
- Unit of Clinical Pharmacology and Regional Pharmacovigilance Center, Department of Clinical and Experimental Medicine ‘Gaetano Salvatore’,, Faculty of Medicine, University ‘Magna Graecia’ Catanzaro, ‘MaterDomini’ University Hospital, Catanzaro, Italy
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28
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Abstract
Palliative care uses several classes of drugs, which are handled by the CYP P450 system. Interaction of drugs in this setting requires ongoing vigilance by the physician. Phenocopying may be more common than previously realized.
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Affiliation(s)
- Stephen A Bernard
- Division of Hematology and Medical Oncology, University of North Carolina, School of Medicine, 3009 Old Clinic Building, CB #7305, Chapel Hill, NC 27599-7305, USA.
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29
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Kirchheiner J, Brøsen K, Dahl ML, Gram LF, Kasper S, Roots I, Sjöqvist F, Spina E, Brockmöller J. CYP2D6 and CYP2C19 genotype-based dose recommendations for antidepressants: a first step towards subpopulation-specific dosages. Acta Psychiatr Scand 2001; 104:173-92. [PMID: 11531654 DOI: 10.1034/j.1600-0447.2001.00299.x] [Citation(s) in RCA: 247] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE This review aimed to provide distinct dose recommendations for antidepressants based on the genotypes of cytochrome P450 enzymes CYP2D6 and CYP2C19. This approach may be a useful complementation to clinical monitoring and therapeutic drug monitoring. METHOD Our literature search covered 32 antidepressants marketed in Europe, Canada, and the United States. We evaluated studies which had compared pharmacokinetic parameters of antidepressants among poor, intermediate, extensive and ultrarapid metabolizers. RESULTS For 14 antidepressants, distinct dose recommendations for extensive, intermediate and poor metabolizers of either CYP2D6 or CYP2C19 were given. For the tricyclic antidepressants, dose reductions around 50% were generally recommended for poor metabolizers of substrates of CYP2D6 or CYP2C19, whereas differences were smaller for the selective serotonin reuptake inhibitors. CONCLUSION We have provided preliminary average dose suggestions based on the phenotype or genotype. This is a first attempt to apply the new pharmacogenetics to suggest dose-regimens that take the differences in drug metabolic capacity into account.
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Affiliation(s)
- J Kirchheiner
- Institute of Clinical Pharmacology, Charité, Humboldt University of Berlin, Germany
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30
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Ereshefsky L, Dugan D. Review of the pharmacokinetics, pharmacogenetics, and drug interaction potential of antidepressants: focus on venlafaxine. Depress Anxiety 2001; 12 Suppl 1:30-44. [PMID: 11098412 DOI: 10.1002/1520-6394(2000)12:1+<30::aid-da4>3.0.co;2-g] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Improving outcomes for patients with depression involves selecting the best possible drug therapy. Considerations relevant to drug product selection include: 1) pharmacokinetic issues such as half-life and time to steady-state, and protein binding; 2) pharmacodynamic drug-drug interactions; and 3) drug metabolism-related drug interactions. A comparison of selected antidepressants with an emphasis on venlafaxine's similarities and differences is presented. Based on these parameters, selecting an antidepressant medication, such as venlafaxine, that has a low potential for drug interactions at the Cytochrome P450 (CYP) enzyme system, and is easy to monitor and dose, facilitate successful treatment of patients. Venlafaxine has been evaluated in clinical studies that demonstrate low to negligible drug interaction potential at CYP2D6, CYP1A2, CYP2C19, and CYP3A4. Its short half-life and time to steady-state, when coupled with the extended release characteristics of the preferred dosage formulation allow for once daily dosing and rapid attainment of therapeutic effects. The CYP3A4 system is involved in both first-pass metabolism and systemic clearance of medications. Drug interactions at this isoenzyme have proven to be of high clinical relevance ranging from cardiovascular toxicity and death with commonly used drugs such as cisapride, to subtherapeutic levels of cyclosporine or protease inhibitors leading to transplant rejection or HIV relapse. Reasons for the under detection and reporting of drug interaction mediated adverse events include healthcare system structure, the poor return to follow up of non-adherent patients, the need for greater education and training of clinicians to recognize drug-related adverse events, and the reluctance of patients to spontaneously communicate about the unpleasant effects of their medication.
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Affiliation(s)
- L Ereshefsky
- College of Pharmacy, University of Texas at Austin, USA.
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31
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Arikian SR, Gorman JM. A Review of the Diagnosis, Pharmacologic Treatment, and Economic Aspects of Anxiety Disorders. PRIMARY CARE COMPANION TO THE JOURNAL OF CLINICAL PSYCHIATRY 2001; 3:110-117. [PMID: 15014608 PMCID: PMC181171 DOI: 10.4088/pcc.v03n0302] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2001] [Accepted: 04/12/2001] [Indexed: 10/20/2022]
Abstract
As many as 1 in 4 Americans will experience an anxiety disorder at some point in their lives, and many will also suffer the depression, substance abuse, distressing physical signs, and socioeconomic problems that often accompany these disorders when left untreated. Anxiety disorders can be detected using simple screening tools in the physician's office. Early and effective treatment with appropriate medication can significantly reduce the psychic and physical symptoms of anxiety, lowering the overall costs of the disorder to the health care system and society. Many drugs offer safe and effective relief of anxiety symptoms with few side effects or drug-drug interactions, and some offer symptomatic relief within 1 to 2 weeks.
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Affiliation(s)
- Steven R. Arikian
- Analytica Group, and the Department of Psychiatry, Columbia University, New York, N.Y
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Amchin J, Ereshefsky L, Zarycranski W, Taylor K, Albano D, Klockowski PM. Effect of venlafaxine versus fluoxetine on metabolism of dextromethorphan, a CYP2D6 probe. J Clin Pharmacol 2001; 41:443-51. [PMID: 11304901 DOI: 10.1177/00912700122010159] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Two antidepressants, venlafaxine and fluoxetine, were evaluated in vivo for their effect on cytochrome P450 2D6 (CYP2D6) activity, measured by the ratio of dextromethorphan, a sensitive CYP2D6 marker, to its metabolite dextrorphan (i.e., DM:DT) excreted in urine after DM coadministration. Twenty-eight healthy extensive metabolizers of CYP2D6 received either venlafaxine (37.5 mg bid for 7 days, then 75 mg bid until Day 28) or fluoxetine (20 mg daily for 28 days); 26 completed the study. Plasma concentrations of both drugs and their active metabolites were determined. DM:DTs were evaluated at baseline (Day 0), on Days 7 and 28 of dosing, and 2 weeks after drug discontinuation (Day 42). Steady-state drug and metabolite levels were achieved in both groups by Day 28. Mean DM:DTs for venlafaxine and fluoxetine differed statistically significantly (p < 0.001) on Days 7, 28, and 42. Comparisons of DM:DT as a percentage of baseline values showed that DM:DT increased 1.2-fold for venlafaxine and 9.1-fold for fluoxetine on Day 7 (p < 0.001) and increased 2.1-fold for venlafaxine and 17.1-fold for fluoxetine on Day 28 (p < 0.001). Inhibition of CYP2D6 metabolism persisted for 2 weeks after discontinuation of fluoxetine, unlike the case with venlafaxine. These in vivo results confirm in vitro data demonstrating significantly weaker inhibition of CYP2D6 with venlafaxine than with fluoxetine. This suggests that clinically significant interactions involving CYP2D6 inhibition could occur between fluoxetine and drugs metabolized by CYP2D6 but may be less likely to occur with venlafaxine.
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Affiliation(s)
- J Amchin
- Wyeth-Ayerst Laboratories, 240 North Radnor-Chester Road, St. Davids, PA 19087, USA
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&NA;. Augmentation strategies in resistant depression - some are effective and well tolerated. DRUGS & THERAPY PERSPECTIVES 2001. [DOI: 10.2165/00042310-200117050-00002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Bickeboeller-Friedrich J, Maurer HH. Screening for detection of new antidepressants, neuroleptics, hypnotics, and their metabolites in urine by GC-MS developed using rat liver microsomes. Ther Drug Monit 2001; 23:61-70. [PMID: 11206046 DOI: 10.1097/00007691-200102000-00012] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A gas chromatography-mass spectrometry (GC-MS) procedure for the detection of new antidepressants, neuroleptics, hypnotics, and their metabolites in urine is presented. The metabolites were first identified in rat liver microsome preparations by GC-MS after isolation and derivatization. Using these GC-MS data, a GC-MS screening was developed for urine as part of the authors' modified systematic toxicologic analysis procedure. After acid hydrolysis of a 2.5-mL aliquot of urine, a further aliquot was added. The mixture was then liquid-liquid extracted at pH 8-9, acetylated, and GC separated. Using mass chromatography with the ions m/z 58, 100, 120, 182, 195, 235, 261, 276, 284. and 293, the presence of new antidepressants, neuroleptics, hypnotics, and their metabolites could be indicated. Positive peaks could be identified by library search using the reference mass spectra recorded during the microsome studies. The intake of therapeutic doses of the following drugs could be monitored in urine: dosulepin, mirtazapine, moclobemide, nefazodone, trazodone, venlafaxine, and zolpidem. Olanzapine and zotepine were detectable in human urine only under steady-state conditions, and low-dose zopiclone was detectable only in overdose. The detection limit was less than 100 ng/mL (signal-to-noise ratio = 3) for the parent drugs.
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Affiliation(s)
- J Bickeboeller-Friedrich
- Department of Experimental and Clinical Toxicology, Institute of Pharmacology and Toxicology, University of Saarland, Homburg (Saar), Germany
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35
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Abstract
Although anxiety and mood disorders are listed as separate disorders in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, they frequently coexist. They may be expressed phenotypically as comorbidities or as the provisional entity mixed anxiety-depressive disorder. Patients with both anxiety and depression are more symptomatic, use more health care resources, and have a worse prognosis than those with a single disorder. Recognizing and treating these patients are challenges for physicians because the symptoms of the two disorders often overlap. Administration of effective treatment, comprising both anxiolytic and antidepressant effects, can reduce patient distress and disability, as well as inappropriate utilization of medical services. Medications such as tricyclic antidepressants, selective serotonin reuptake inhibitors, nefazodone, venlafaxine XR (extended release) and mirtazapine, are highly effective in treating comorbid depression and anxiety. These newer agents now represent the pharmacotherapeutic treatments of choice for the comorbid conditions.
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Affiliation(s)
- M H Pollack
- Massachusetts General Hospital Anxiety Disorders Program, Boston, MA, USA
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36
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Albers LJ, Reist C, Vu RL, Fujimoto K, Ozdemir V, Helmeste D, Poland R, Tang SW. Effect of venlafaxine on imipramine metabolism. Psychiatry Res 2000; 96:235-43. [PMID: 11084219 DOI: 10.1016/s0165-1781(00)00213-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The present study was designed to determine the effect of venlafaxine on imipramine metabolism in an attempt to elucidate the potential for cytochrome P450 drug-drug interactions with venlafaxine. We examined the metabolism of a single 100-mg dose of imipramine before and after treatment with venlafaxine, 50 mg three times a day. Eight male subjects were phenotyped for CYP2D6 activity. Two subjects were poor metabolizers of dextromethophan, and data from the remaining six subjects (mean age=45.3+/-15) were analyzed. Venlafaxine increased imipramine C(max) and elevated AUC by 40%. Desipramine clearance and volume of distribution were reduced by 20% and 25%, respectively. These findings are consistent with a statistically significant, but clinically modest impact of venlafaxine on CYP2D6-metabolized substrates.
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Affiliation(s)
- L J Albers
- Department of Psychiatry, University of California, California College of Medicine, Irvine, CA 92697, USA
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37
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Abstract
Cisapride, a prokinetic agent, has been used for the treatment of a number of gastrointestinal disorders, particularly gastro-oesophageal reflux disease in adults and children. Since 1993, 341 cases of ventricular arrhythmias, including 80 deaths, have been reported to the US Food and Drug Administration. Marketing of the drug has now been discontinued in the US; however, it is still available under a limited-access protocol. Knowledge of the risk factors for cisapride-associated arrhythmias will be essential for its continued use in those patients who meet the eligibility criteria. This review summarises the published literature on the pharmacokinetic and pharmacodynamic interactions of cisapride with concomitantly administered drugs, providing clinicians with practical recommendations for avoiding these potentially fatal events. Pharmacokinetic interactions with cisapride involve inhibition of cytochrome P450 (CYP) 3A4, the primary mode of elimination of cisapride, thereby increasing plasma concentrations of the drug. The macrolide antibacterials clarithromycin, erythromycin and troleandomycin are inhibitors of CYP3A4 and should not be used in conjunction with cisapride. Azithromycin is an alternative. Similarly, azole antifungal agents such as fluconazole, itraconazole and ketoconazole are CYP3A4 inhibitors and their concomitant use with cisapride should be avoided. Of the antidepressants nefazodone and fluvoxamine should be avoided with cisapride. Data with fluoxetine is controversial, we favour the avoidance of its use. Citalopram, paroxetine and sertraline are alternatives. The HIV protease inhibitors amprenavir, indinavir, nelfinavir, ritonavir and saquinavir inhibit CYP3A4. Clinical experience with cisapride is lacking but avoidance with all protease inhibitors is recommended, although saquinavir is thought to have clinically insignificant effects on CYP3A4. Delavirdine is also a CYP3A4 inhibitor and should be avoided with cisapride. We also recommend avoiding coadministration of cisapride with amiodarone, cimetidine (alternatives are famotidine, nizatidine, ranitidine or one of the proton pump inhibitors), diltiazem and verapamil (the dihydropyridine calcium antagonists are alternatives), grapefruit juice, isoniazid, metronidazole, quinine, quinupristin/dalfopristin and zileuton (montelukast is an alternative). Pharmacodynamic interactions with cisapride involve drugs that have the potential to have additive effects on the QT interval. We do not recommend use of cisapride with class Ia and III antiarrhythmic drugs or with adenosine, bepridil, cyclobenzaprine, droperidol, haloperidol, nifedipine (immediate release), phenothiazine antipsychotics, tricyclic and tetracyclic antidepressants or vasopressin. Vigilance is advised if anthracyclines, cotrimoxazole (trimethoprim-sulfamethoxazole), enflurane, halothane, isoflurane, pentamidine or probucol are used with cisapride. In addition, uncorrected electrolyte disturbances induced by diuretics may increase the risk of torsade de pointes. Patients receiving cisapride should be promptly treated for electrolyte disturbances.
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Affiliation(s)
- E L Michalets
- Mission + St Joseph's Health System, Department of Pharmacy, Asheville, North Carolina 28801, USA.
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38
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Gareri P, Falconi U, De Fazio P, De Sarro G. Conventional and new antidepressant drugs in the elderly. Prog Neurobiol 2000; 61:353-96. [PMID: 10727780 DOI: 10.1016/s0301-0082(99)00050-7] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Depression in the elderly is nowadays a predominant health care problem, mainly due to the progressive aging of the population. It results from psychosocial stress, polypathology, as well as some biochemical changes which occur in the aged brain and can lead to cognitive impairments, increased symptoms from medical illness, higher utilization of health care services and increased rates of suicide and nonsuicide mortality. Therefore, it is very important to make an early diagnosis and a suitable pharmacological treatment, not only for resolving the acute episode, but also for preventing relapse and enhancing the quality of life. Age-related changes in pharmacokinetics and in pharmacodynamics have to be kept into account before prescribing an antidepressant therapy in an old patient. In this paper some of the most important and tolerated drugs in the elderly are reviewed. Tricyclic antidepressants have to be used carefully for their important side effects. Nortriptyline, amytriptiline, clomipramine and desipramine as well, seem to be the best tolerated tricyclics in old people. Second generation antidepressants are preferred for the elderly and those patients with heart disease as they have milder side effects and are less toxic in overdose and include the so called atypicals, such as selective serotonin reuptake inhibitors, serotonin noradrenalene reuptake inhibitors and noradrenaline reuptake inhibitors. Monoamine oxidase (MAO) inhibitors are useful drugs in resistant forms of depression in which the above mentioned drugs have no efficacy; the last generation drugs (reversible MAO inhibitors), such as meclobemide, seem to be very successful. Mood stabilizing drugs are widely used for preventing recurrences of depression and for preventing and treating bipolar illness. They include lithium, which is sometimes used especially to prevent recurrence of depression, even if its use is limited in old patients for its side effects, the anticonvulsants carbamazepine and valproic acid. Putative last generation mood stabilizing drugs include the dihydropyridine L-type calcium channel blockers and the anticonvulsants phenytoin, lamotrigine, gabapentin and topiramate, which have unique mechanisms of action and also merit further systematic study. Psychotherapy is often used as an adjunct to pharmacotherapy, while electroconvulsant therapy is used only in the elderly patients with severe depression, high risk of suicide or drug resistant forms.
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Affiliation(s)
- P Gareri
- Chair of Pharmacology and Chair of Psychiatry, Department of Clinical and Experimental Medicine "Gaetano Salvatore", Faculty of Medicine, University of Catanzaro, Policlinico Materdomini, via Tommaso Campanella, 88100, Catanzaro, Italy
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Ballenger JC. Anxiety and Depression: Optimizing Treatments. PRIMARY CARE COMPANION TO THE JOURNAL OF CLINICAL PSYCHIATRY 2000; 2:71-79. [PMID: 15014652 PMCID: PMC181112 DOI: 10.4088/pcc.v02n0301] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2000] [Accepted: 06/06/2000] [Indexed: 10/20/2022]
Abstract
Properly diagnosing and treating patients with anxiety, depression, or both is a challenging aspect of practicing medicine in the primary care setting. Patients often present with somatic complaints rather than classic psychiatric symptoms. In addition, there is significant overlap between anxiety and depression in this patient population. Comorbid anxiety and depression is often more resistant to pharmacologic treatment, and patients with coexisting disorders have a poorer medical prognosis than do patients with either disorder alone. Fortunately, many new therapies are available to assist the clinician in managing these patients. The newer antidepressants, in particular, are playing an increasingly important role in the treatment of both anxiety disorders alone and comorbid anxiety and depression. These new choices enable our goal of treatment to encompass not only improvement but also sustained complete remission. Of the newer agents, the selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors have been studied quite extensively in these patient populations. The specific profiles of individual agents may assist the clinician in individualizing treatment. Characteristics such as robust efficacy, speed of onset of activity, the potential for drug-drug interactions, dose response, and tolerability are important considerations in optimizing treatment.
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Affiliation(s)
- James C. Ballenger
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston
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Gelenberg AJ. Psychiatric and Somatic Markers of Anxiety: Identification and Pharmacologic Treatment. PRIMARY CARE COMPANION TO THE JOURNAL OF CLINICAL PSYCHIATRY 2000; 2:49-54. [PMID: 15014583 PMCID: PMC181205 DOI: 10.4088/pcc.v02n0204] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2000] [Accepted: 03/20/2000] [Indexed: 10/20/2022]
Abstract
Anxiety disorders are widely prevalent but insufficiently recognized and inadequately treated in primary care practice. The annual costs of morbidity and mortality of these disorders approach $50 billion, substantially more than costs for schizophrenia or all affective disorders combined. Somatization of anxiety contributes to the challenges of making an accurate diagnosis and to the indirect costs associated with delaying appropriate treatment. Pharmacologic interventions give clinicians the necessary tools to treat anxiety safely and effectively. Former therapeutic choices were limited to benzodiazepines, buspirone, and older antidepressants, but newer anxiolytic agents have become available. The selective serotonin reuptake inhibitors and agents with dual reuptake inhibition, such as venlafaxine XR, are optimizing therapy and yielding less risk for serious adverse events, greater safety in long-term therapy, and opportunity for improved patient compliance. These newer antidepressants provide substantial efficacy in patients with comorbid anxiety and depression, commonly seen in the primary care setting.
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Abstract
PURPOSE This review of drug interactions in palliative care examines the relevant literature in this area and summarizes the information on interactions of drugs, nutrients, and natural products that are used in the palliative care setting. Particular emphasis is placed on describing the newer information on the cytochrome P450 (CYP) system and the interactions of opioids, antidepressants, and the antitussive, dextromethorphan. METHODS We performed a search of the MEDLINE database of the time period from 1966 until April 1998, using medical subject headings such as the names of selective serotonin reuptake inhibitors and other relevant medications in palliative care. Literature reviewed included both human and animal articles as well as non-English literature. Bibliographies of these articles and the personal libraries of several palliative care specialists were reviewed. Software developed by The Medical Letter-The Drug Interaction Program was also used. RESULTS Drug interactions can be categorized in several ways. Drug-drug interactions are the most well known and can be kinetic, dynamic, or pharmaceutical. Pharmacokinetic interactions can involve CYP 2D6, which acts on drugs such as codeine and is responsible for its conversion to morphine. Poor metabolizers, either genotypic or due to phenocopying, are at risk for undertreatment if not recognized. Pharmacodynamic interactions with dextromethorphan may produce serotonin syndrome. CONCLUSION Drug interactions are important in palliative care as in other aspects of medicine. These interactions are similar to those seen in other areas of medical care but have significant consequences in pain management. Failure to recognize these interactions can lead to either overdosing or undertreatment.
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Affiliation(s)
- S A Bernard
- Division of Hematology/Medical Oncology, University of North Carolina, Chapel Hill, NC, USA
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42
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Alfaro CL, Lam YWF, Simpson J, Ereshefsky L. CYP2D6 Inhibition by Fluoxetine, Paroxetine, Sertraline, and Venlafaxine in a Crossover Study: Intraindividual Variability and Plasma Concentration Correlations. J Clin Pharmacol 2000. [DOI: 10.1177/009127000004000108] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Cam L. Alfaro
- Departments of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
- College of Pharmacy, University of Texas at Austin, Austin, Texas
- National Institutes of Health Clinical Center Pharmacy Department, Bethesda, Maryland
| | - Y. W. Francis Lam
- Departments of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
- Departments of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas
- College of Pharmacy, University of Texas at Austin, Austin, Texas
| | | | - Larry Ereshefsky
- Departments of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
- Departments of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, Texas
- College of Pharmacy, University of Texas at Austin, Austin, Texas
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43
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Review of Antidepressant Medications. Oral Maxillofac Surg Clin North Am 1999. [DOI: 10.1016/s1042-3699(20)30246-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Avenoso A, Facciolà G, Scordo MG, Spina E. No effect of the new antidepressant reboxetine on CYP2D6 activity in healthy volunteers. Ther Drug Monit 1999; 21:577-9. [PMID: 10519458 DOI: 10.1097/00007691-199910000-00015] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The effect of the new antidepressant reboxetine on the activity of the cytochrome P450 (CYP) 2D6 isoenzyme was investigated in 10 healthy volunteers using dextromethorphan as a model CYP2D6 substrate. Each volunteer received a single 30 mg oral dose of dextromethorphan on three different occasions separated by an interval of at least 4 weeks: a) in a control session; b) after 1 week of treatment with reboxetine, 8 mg/day; and c) after 1 week of treatment with paroxetine (an inhibitor of CYP2D6 activity) 20 mg/day. Urine was collected over the next 8 hours for the determination of the dextromethorphan/dextrorphan metabolic ratio. All subjects were classified as extensive metabolizers (EM) with a dextromethorphan/dextrorphan ratio < 0.3. There were no notable changes in the urinary dextromethorphan/dextrorphan ratio in the reboxetine phase as compared to the control session. By contrast, there was a statistically significant increase in the metabolic ratio in the paroxetine phase (p < 0.001), with 4 subjects switching to poor metabolizer (PM) phenotype. These results suggest that reboxetine is unlikely to cause clinically significant interactions with substrates of CYP2D6.
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Affiliation(s)
- A Avenoso
- Institute of Pharmacology, University of Messina, Italy
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45
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Reznik I, Rosen Y, Rosen B. An acute ischaemic event associated with the use of venlafaxine: a case report and proposed pathophysiological mechanisms. J Psychopharmacol 1999; 13:193-5. [PMID: 10475726 DOI: 10.1177/026988119901300212] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Venlafaxine, a structurally novel antidepressant, belongs to a new generation of antidepressants--the serotonin/noradrenaline reuptake inhibitors. In clinical trials, venlafaxine was found safe and effective in most patients. However, significant changes in vital signs (hyper- and hypotension) and cardiac conduction abnormalities were observed in a few patients, notably in elderly patients. We present a case of an elderly woman with a pre-existing history of ischaemic heart disease, who was treated with venlafaxine, and developed acute myocardial ischaemia within the first week of treatment. This is the first report of a possible association between an acute cardiovascular event and venlafaxine. The association of venlafaxine treatment with ischaemic events could be explained by its unique pharmacological and haemodynamic properties.
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Affiliation(s)
- I Reznik
- Abarbanel Mental Health Centre, Rabin Medical Centre-Beilinson Campus, Petah-Tikva, Israel.
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46
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Rotzinger S, Bourin M, Akimoto Y, Coutts RT, Baker GB. Metabolism of some "second"- and "fourth"-generation antidepressants: iprindole, viloxazine, bupropion, mianserin, maprotiline, trazodone, nefazodone, and venlafaxine. Cell Mol Neurobiol 1999; 19:427-42. [PMID: 10379419 DOI: 10.1023/a:1006953923305] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
1. This review summarizes the major known aspects of the metabolism of second-generation (iprindole, viloxazine, bupropion, mianserin, maprotiline, and trazodone) and fourth-generation (nefazodone and venlafaxine) antidepressants. 2. Discussions about specific enzymes involved and about possible pharmacokinetic drug-drug interactions, particularly as they relate to cytochrome P450 enzymes, are provided.
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Affiliation(s)
- S Rotzinger
- Department of Psychiatry, University of Alberta, Edmonton, Canada
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47
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Amchin J, Zarycranski W, Taylor KP, Albano D, Klockowski PM. Effect of Venlafaxine on CYP1A2‐Dependent Pharmacokinetics and Metabolism of Caffeine. J Clin Pharmacol 1999. [DOI: 10.1177/009127009903900308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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48
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Davidson JRT. USING VENLAFAXINE HYDROCHLORIDE TO TREAT ANXTETY. Psychiatr Ann 1999. [DOI: 10.3928/0048-5713-19990301-04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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49
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Amchin J, Zarycranski W, Taylor KP, Albano D, Klockowski PM. Effect of Venlafaxine on the Pharmacokinetics of Risperidone. J Clin Pharmacol 1999. [DOI: 10.1177/009127009903900314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Jess Amchin
- From Wyeth‐Ayerst Laboratories, Philadelphia
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50
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Schweitzer I, Tuckwell V. Risk of adverse events with the use of augmentation therapy for the treatment of resistant depression. Drug Saf 1998; 19:455-64. [PMID: 9880089 DOI: 10.2165/00002018-199819060-00003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Augmentation therapy is used for those situations where a patient's depression is either treatment-resistant, or partially and/or insufficiently responsive to treatment. It also may be used to attempt to induce a more rapid treatment response. Using drugs together may increase the risk of adverse effects, through potentiation of existing adverse effects or alterations in plasma concentrations of the drug. It is important that clinicians are aware of potential risks of augmentation therapy. Lithium augmentation of a tricyclic antidepressant is relatively well tolerated and the dangers are no greater than using these medications on their own. There are also no reports of serious adverse events when lithium is added to a monoamine oxidase inhibitor. With lithium augmentation of selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor (SSRI) therapy there have been case reports of the development of a central serotonin syndrome, and thus caution must exercised. A serious concern when using a tricyclic antidepressant to augment an SSRI is the effect of the SSRI on the cytochrome P450 system and the resulting significant increase in tricyclic antidepressant blood concentrations. Augmentation with thyroid hormones appears to be well tolerated and effective. Case reports and open studies indicate that augmentation with buspirone and the psychostimulants, carbamazepine and valproic acid (valproate sodium) is effective and results in minimal adverse effects. However, there is no empirical evidence supporting these results. Recent work supports the tolerability and efficacy of pindolol augmentation. Considerable caution should be exercised when combining psychotropic drugs. The practitioner should only do so with a full knowledge of the compounds involved and their pharmacological properties.
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Affiliation(s)
- I Schweitzer
- University of Melbourne and Professional Unit, The Melbourne Clinic, Richmond, Victoria, Australia.
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