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Schmid Y, Navarini A, Thomas ZRM, Pfleiderer B, Krähenbühl S, Mueller SM. Sex differences in the pharmacology of itch therapies-a narrative review. Curr Opin Pharmacol 2019; 46:122-142. [PMID: 31299512 DOI: 10.1016/j.coph.2019.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 05/17/2019] [Indexed: 02/08/2023]
Abstract
BACKGROUND Chronic itch is the most common skin-related condition, associated with a high psychosocial and economic burden. In recent years, increasing evidence of sex differences in the perception, clinical presentation and treatment requirements of itch points towards potential benefits when using sex-adapted therapies. It is well-known that body composition, absorption, metabolism, elimination and adverse drug reactions (ADRs) differ between sexes, but only little is known about the impact of sex in the pharmacology of itch treatments, which could help to rationalise sex-adapted treatment strategies. AIM To evaluate and review sex effects in the pharmacokinetics and /-dynamics of drugs used to treat itch. METHODS In this narrative review we performed a PubMed and MEDLINE (Ovid) search using the terms (itch OR pruritus) AND (gender OR sex) AND (drug OR medication OR pharmacokinetics OR pharmacodynamics). Additional searches were performed for the topical and systemic drugs recommended by the European Guideline on Chronic Pruritus. RESULTS We found numerous reports with variable levels of evidence of sex effects with respect to the pharmacokinetics and/or pharmacodynamics of 14 drug classes used for the treatment of itch, including a total of 19 systemic and 3 topical drugs. Women seem to present higher plasma levels of several drugs used in itch treatment, including tri- and tetracyclic antidepressants (e.g. doxepin, amitriptyline, mirtazapine), serotonin reuptake inhibitors (e.g. paroxetine, sertraline, fluoxetine), immunosuppressive drugs (e.g. cyclosporine, mycophenolate mofetil), serotonin receptor antagonists (e.g. ondansetron) and betablockers (e.g. propranolol). Adverse drug reactions (ADRs) were generally more common in women. Being female was reported to be an independent risk factor for QTc-prolongation associated with antihistamines and tetracyclic antidepressants. Additionally, women seem to be more prone to sedative effects of antihistamines, and to suffer from a higher frequency as well as severity of side effects with systemic calcineurin inhibitors, opioid agonists, and opioid antagonists. Women were also sensitised more often to topically applied drugs. Of note, apart from only one experimental study with capsaicin, none of these reports were designed specifically to assess the effect of sex (and gender) in the treatment of itch. DISCUSSION/CONCLUSION Our review supports previous reports that sex is of importance in the pharmacokinetics and /-dynamics of several drugs used to treat itch although those drugs were mostly evaluated for non-itch indications. However, the results are limited by methodological limitations evident in most studies such as underrepresentation of women in clinical trials. This emphasises the need to study the impact of sex (and gender) in future itch trials to yield better outcomes and prevent ADRs in both sexes.
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Affiliation(s)
- Yasmin Schmid
- Clinical Pharmacology & Toxicology, University Hospital Basel, Switzerland
| | | | | | - Bettina Pfleiderer
- Department of Clinical Radiology, University Hospital Münster and Medical Faculty, University of Münster, Germany; Competence Center Chronic Pruritus (KCP), University of Muenster, Germany
| | - Stephan Krähenbühl
- Clinical Pharmacology & Toxicology, University Hospital Basel, Switzerland
| | - Simon M Mueller
- Department of Dermatology, University Hospital Basel, Switzerland.
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Murray M, Zhou F. Trafficking and other regulatory mechanisms for organic anion transporting polypeptides and organic anion transporters that modulate cellular drug and xenobiotic influx and that are dysregulated in disease. Br J Pharmacol 2017; 174:1908-1924. [PMID: 28299773 DOI: 10.1111/bph.13785] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/01/2017] [Accepted: 03/05/2017] [Indexed: 12/25/2022] Open
Abstract
Organic anion transporters (OATs) and organic anion-transporting polypeptides (OATPs), encoded by a number of solute carrier (SLC)22A and SLC organic anion (SLCO) genes, mediate the absorption and distribution of drugs and other xenobiotics. The regulation of OATs and OATPs is complex, comprising both transcriptional and post-translational mechanisms. Plasma membrane expression is required for cellular substrate influx by OATs/OATPs. Thus, interest in post-translational regulatory processes, including membrane targeting, endocytosis, recycling and degradation of transporter proteins, is increasing because these are critical for plasma membrane expression. After being synthesized, transporters undergo N-glycosylation in the endoplasmic reticulum and Golgi apparatus and are delivered to the plasma membrane by vesicular transport. Their expression at the cell surface is maintained by de novo synthesis and recycling, which occurs after clathrin- and/or caveolin-dependent endocytosis of existing protein. Several studies have shown that phosphorylation by signalling kinases is important for the internalization and recycling processes, although the transporter protein does not appear to be directly phosphorylated. After internalization, transporters that are targeted for degradation undergo ubiquitination, most likely on intracellular loop residues. Epigenetic mechanisms, including methylation of gene regulatory regions and transcription from alternate promoters, are also significant in the regulation of certain SLC22A/SLCO genes. The membrane expression of OATs/OATPs is dysregulated in disease, which affects drug efficacy and detoxification. Several transporters are expressed in the cytoplasmic subcompartment in disease states, which suggests that membrane targeting/internalization/recycling may be impaired. This article focuses on recent developments in OAT and OATP regulation, their dysregulation in disease and the significance for drug therapy.
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Affiliation(s)
- Michael Murray
- Pharmacogenomics and Drug Development Group, Discipline of Pharmacology, School of Medical Sciences, The University of Sydney, NSW, 2006, Australia
| | - Fanfan Zhou
- Faculty of Pharmacy, The University of Sydney, NSW, 2006, Australia
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3
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Morrissey KM, Stocker SL, Wittwer MB, Xu L, Giacomini KM. Renal Transporters in Drug Development. Annu Rev Pharmacol Toxicol 2013; 53:503-29. [DOI: 10.1146/annurev-pharmtox-011112-140317] [Citation(s) in RCA: 239] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kari M. Morrissey
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158; , , , ,
| | - Sophie L. Stocker
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158; , , , ,
| | - Matthias B. Wittwer
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158; , , , ,
| | - Lu Xu
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158; , , , ,
| | - Kathleen M. Giacomini
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158; , , , ,
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Meetam P, Srimaroeng C, Soodvilai S, Chatsudthipong V. Regulatory role of testosterone in organic cation transport: in vivo and in vitro studies. Biol Pharm Bull 2009; 32:982-7. [PMID: 19483302 DOI: 10.1248/bpb.32.982] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The renal proximal tubule (RPT) plays a crucial role in organic cation (OC) secretion and has a major impact on pharmacokinetics of OC drugs. Secretory transport is vectorial. Thus, it involves transporters located at both basolateral and apical membranes. Although sex hormones have been shown to regulate OC transport, there is little data on the effect of testosterone on OC secretion in a whole animal. Therefore, we determined the clearance of tetraethylammonium (TEA), a model OC substrate, in intact and castrated male mice. Castration significantly decreased renal TEA secretion by 30%, and testosterone supplementation returned TEA secretion to control levels in castrated mice. The mechanism of this effect was further examined in isolated mouse renal proximal tubules (mRPT). TEA uptake in isolated mRPT from castrated mice was reduced by 36%. This effect was reversed in tubules from castrated mice supplemented with testosterone. Kinetic analysis of [(3)H]-TEA uptake in isolated mRPT showed a decreased V(max) with no change in K(m), implying that the decrease in transport rate was caused by lowering in the number of transporters in castrated mice rather than a change in transporter affinity. Quantitative real time polymerase chain reaction (real time PCR) revealed that organic cation transporter (OCT)2 is the major TEA transporter in male mice. Moreover, OCT2 mRNA level was significantly reduced after castration. Castrated mice also showed a modest increase in organic cation/carnitine transporter 1 (OCTN1) mRNA level, indicating that testosterone may also regulate apical OCTN1 expression. These data suggest that testosterone regulates transepithelial transport of OC through modulation of OCT2 expression in male mice.
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Affiliation(s)
- Paranee Meetam
- Department of Physiology, Faculty of Science, Mahidol University
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5
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Nicolas JM, Espie P, Molimard M. Gender and interindividual variability in pharmacokinetics. Drug Metab Rev 2009; 41:408-21. [DOI: 10.1080/10837450902891485] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Sitar DS. Adventures in drug disposition: pas seulement pâté de foie. Can J Physiol Pharmacol 2007; 85:1215-25. [PMID: 18066123 DOI: 10.1139/y07-121] [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
Interindividual variability in drug disposition and effect has served to confound the optimization of drug therapy. Over my career, I have focused on delineating mechanisms that contribute to this variability, with the goal of improving the benefit : risk ratio when drug therapy is chosen as an intervention strategy. In this manuscript, I present some of our experimental findings that I believe have contributed to an increased understanding of variability in drug disposition and efficacy.
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Affiliation(s)
- Daniel S Sitar
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Centre on Aging, University of Manitoba, A220-753 McDermot Avenue, Winnipeg, MB R3E 0T6, Canada.
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7
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Pelis RM, Hartman RC, Wright SH, Wunz TM, Groves CE. Influence of estrogen and xenoestrogens on basolateral uptake of tetraethylammonium by opossum kidney cells in culture. J Pharmacol Exp Ther 2007; 323:555-61. [PMID: 17684116 DOI: 10.1124/jpet.107.126748] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The sex steroid hormone estrogen down-regulates renal organic cation (OC) transport in animals, and it may contribute to sex-related differences in xenobiotic accumulation and excretion. Also, the presence of various endocrine-disrupting chemicals, i.e., environmental chemicals that possess estrogenic activity (e.g., xenoestrogens) may down-regulate various transporters involved in renal accumulation and excretion of xenobiotics. The present study characterizes the mechanism by which long-term (6-day) incubation with physiological concentrations of 17beta-estradiol (E(2)) or the xenoestrogens diethylstilbestrol (DES) and bisphenol A (BPA) regulates the basolateral membrane transport of the OC tetraethylammonium (TEA) in opossum kidney (OK) cell renal cultures. Both 17beta-E(2) and the xenoestrogen DES produced a dose- and time-dependent inhibition of basolateral TEA uptake in OK cell cultures, whereas the weakly estrogenic BPA had no effect on TEA uptake. Treatment for 6 days with either 1 nM 17beta-E(2) or DES reduced TEA uptake by approximately 30 and 40%, respectively. These effects were blocked completely by the estrogen receptor antagonist ICI 182780 (Faslodex, fulvestrant), suggesting that these estrogens regulate OC transport through the estrogen receptor, which was detected (estrogen receptor alpha) in OK cell cultures by reverse transcription-polymerase chain reaction. The J(max) value for TEA uptake in 17beta-E(2)- and DES-treated OK cell cultures was approximately 40 to 50% lower than for ethanol-treated cultures, whereas K(t) was unaffected. This reduction in transport capacity was correlated with a reduction in OC transporter OCT1 protein expression following treatment with both agents.
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Affiliation(s)
- Ryan M Pelis
- Department of Physiology, The University of Arizona, Tucson, AZ 85724, USA.
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Sabolić I, Asif AR, Budach WE, Wanke C, Bahn A, Burckhardt G. Gender differences in kidney function. Pflugers Arch 2007; 455:397-429. [PMID: 17638010 DOI: 10.1007/s00424-007-0308-1] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Revised: 06/12/2007] [Accepted: 06/14/2007] [Indexed: 01/04/2023]
Abstract
Sex hormones influence the development of female (F) and male (M) specific traits and primarily affect the structure and function of gender-specific organs. Recent studies also indicated their important roles in regulating structure and/or function of nearly every tissue and organ in the mammalian body, including the kidneys, causing gender differences in a variety of characteristics. Clinical observations in humans and studies in experimental animals in vivo and in models in vitro have shown that renal structure and functions under various physiological, pharmacological, and toxicological conditions are different in M and F, and that these differences may be related to the sex-hormone-regulated expression and action of transporters in the apical and basolateral membrane of nephron epithelial cells. In this review we have collected published data on gender differences in renal functions, transporters and other related parameters, and present our own microarray data on messenger RNA expression for various transporters in the kidney cortex of M and F rats. With these data we would like to emphasize the importance of sex hormones in regulation of a variety of renal transport functions and to initiate further studies of gender-related differences in kidney structure and functions, which would enable us to better understand occurrence and development of various renal diseases, pharmacotherapy, and drug-induced nephrotoxicity in humans and animals.
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Affiliation(s)
- Ivan Sabolić
- Molecular Toxicology, Institute for Medical Research and Occupational Health, Zagreb, Croatia.
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Asaka JI, Terada T, Okuda M, Katsura T, Inui KI. Androgen receptor is responsible for rat organic cation transporter 2 gene regulation but not for rOCT1 and rOCT3. Pharm Res 2006; 23:697-704. [PMID: 16550473 DOI: 10.1007/s11095-006-9665-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Accepted: 12/07/2005] [Indexed: 01/11/2023]
Abstract
PURPOSE Organic cation transporters 1-3 (OCT1-3; Slc22a1-3) mediate the membrane transport of organic cations in the kidney. We previously reported that rat (r)OCT2 expression in the kidney was regulated by testosterone. In this study, we examined the transcriptional mechanisms underlying the testosterone-dependent regulation of rOCT2 expression. METHODS Approximately 3000-bp fragments of the rOCT1-3 promoter region were isolated, and promoter activities were measured in the renal epithelial cell line LLC-PK1 with the coexpression of rat androgen receptor. RESULTS Among reporter constructs tested, only rOCT2 promoter activity was stimulated by testosterone. This stimulation was suppressed by nilutamide, an antiandrogen drug. Reporter assays using deletion constructs and mutational constructs of putative androgen response elements (ARE) in the rOCT2 promoter region suggested that two AREs, located at approximately -3000 and -1300, respectively, play an important role in the induction by testosterone. CONCLUSIONS Testosterone induces the expression of rOCT2, but not of rOCT1 and rOCT3, via the AR-mediated transcriptional pathway. This is the first study to address the transcriptional mechanisms of testosterone-dependent gene regulation of the Slc22 family.
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Affiliation(s)
- Jun-ichi Asaka
- Department of Pharmacy, Kyoto University Hospital, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto, 606-8507, Japan
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10
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Groves CE, Suhre WB, Cherrington NJ, Wright SH. Sex Differences in the mRNA, Protein, and Functional Expression of Organic Anion Transporter (Oat) 1, Oat3, and Organic Cation Transporter (Oct) 2 in Rabbit Renal Proximal Tubules. J Pharmacol Exp Ther 2005; 316:743-52. [PMID: 16249371 DOI: 10.1124/jpet.105.094979] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Sex differences in transport of the organic anion (OA) substrate p-aminohippurate (PAH) and the organic cation (OC) substrate tetraethylammonium (TEA) have been recognized for some time. In the rat kidney, androgens up-regulate and estrogens down-regulate PAH and TEA transport, which correlate with similar changes in mRNA and protein expression for the renal basolateral membrane transporters organic anion transporter (Oat) 1 and organic cation transporter (Oct) 2. However, these sex differences are not readily demonstrated in other species. The present study characterizes the kinetics of basolateral membrane PAH, estrone sulfate (ES), and TEA uptake in renal proximal tubule (RPT) suspensions isolated from female and male rabbits to compare functional expression of transport with mRNA and protein expression for rbOat1, rbOat3, and rbOct2. Although rbOat1-rbOat3 mRNA expression exhibited developmental differences, no sex differences in mRNA levels were observed. Oat1 and Oat3 protein expression in RPT suspensions also was similar between adult female and male rabbits. In contrast, rbOct1 and rbOct2 mRNA levels did not show developmental differences, but rbOct2 mRNA expression was greater in adult male than female rabbits. However, the sex difference in rbOct2 mRNA level did not translate to rbOct2 protein expression. Importantly, functional expression of Oat1, Oat3, and Oct2 transport as measured by kinetics (J(max) and K(t)) of PAH, ES, and TEA uptake was similar between adult male and female rabbits, and correlated with rbOat1, rbOat3, and rbOct2 protein expression. Thus, unlike rodents, rabbit renal OA and OC transport does not exhibit sex differences, pointing to the need for caution in extrapolating transport-related sex differences between species.
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Affiliation(s)
- Carlotta E Groves
- Department of Physiology, University of Arizona, Tucson, 85724, USA.
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11
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Anderson GD. Sex and racial differences in pharmacological response: where is the evidence? Pharmacogenetics, pharmacokinetics, and pharmacodynamics. J Womens Health (Larchmt) 2005; 14:19-29. [PMID: 15692274 DOI: 10.1089/jwh.2005.14.19] [Citation(s) in RCA: 205] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The Food and Drug Administration (FDA) reviewed 300 new drug applications between 1995 and 2000. Of the 163 that included a sex analysis, 11 drugs showed a >40% difference in pharmacokinetics between males and females, which was listed on the product label, yet no dosing recommendations were made based on sex. Female sex has been shown to be a risk factor for clinically relevant adverse drug reactions. Would simply dosing females based on their different pharmacokinetics decrease the incidence of adverse events? The answer is not known. Sex-dependent pharmacodynamic effects have been identified. The role of pharmacokinetics vs. pharmacodynamics is unclear, as is the impact of pharmacogenetics on both. This review highlights a few specific examples in each area in which sex differences in pharmacokinetics and pharmacodynamics are important and provides recommendations for additional needed research.
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Affiliation(s)
- Gail D Anderson
- Department of Pharmacy, University of Washington, Seattle, Washington, USA.
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12
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Fife DJ, Maibach HI. Gender Differences in the Pharmacokinetics of Oral Dermatologic Medications. ACTA ACUST UNITED AC 2004. [DOI: 10.1081/cus-120030169] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Morris ME, Lee HJ, Predko LM. Gender differences in the membrane transport of endogenous and exogenous compounds. Pharmacol Rev 2003; 55:229-40. [PMID: 12773628 DOI: 10.1124/pr.55.2.1] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Gender differences have been well described in pharmacokinetics and contribute to the interindividual variation in drug disposition, therapeutic response, and drug toxicity. Sex-related differences in the membrane transport of endogenous substrates and xenobiotics have been reported in various organs of the body including kidney, liver, intestine, and brain. These gender-related differences in transport systems could also contribute to interindividual variability in pharmacokinetics and pharmacodynamics. This review will focus on current knowledge of gender-associated differences in the transport of endogenous and exogenous compounds in a variety of body organs and will discuss the implications and the clinical significance of these observations.
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Affiliation(s)
- Marilyn E Morris
- Department of Pharmaceutical Sciences, 527 Hochstetter Hall, University at Buffalo, Amherst, NY 14260-1200, USA.
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McGeer A, Sitar DS, Tamblyn SE, Faron K, Orr P, Aoki FY. Use of antiviral prophylaxis in influenza outbreaks in long term care facilities. Can J Infect Dis 2000; 11:187-92. [PMID: 18159289 PMCID: PMC2094769 DOI: 10.1155/2000/246037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Influenza is a major cause of illness and death in residents of long term care facilities for the elderly, in part because residents' age and underlying illness increase the risk of serious complications, and in part because institutional living increases the risk of influenza outbreaks. The administration of antiviral medications active against influenza to persons exposed to influenza has been shown to protect them effectively from illness, and mass antiviral prophylaxis of residents is an effective means of terminating influenza A outbreaks in long term care facilities. The only antiviral currently licensed in Canada for influenza prophylaxis is amantadine, a medication active against influenza A but not influenza B. The National Advisory Committee on Immunization recommends that amantadine prophylaxis be offered to residents when influenza A outbreaks occur in long term care facilities. However, there remain a number of unanswered questions about how best to use amantadine for controlling influenza A outbreaks in long term care facilities. In addition, two members of a new class of antivirals called neuraminidase inhibitors have recently been licensed in Canada for the treatment of influenza, and are effective in prophylaxis. Issues in the use of amantadine in the control of outbreaks of influenza A in long term care facilities for the elderly are reviewed, and the potential uses of neuraminidase inhibitors in this setting are discussed.
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Affiliation(s)
- Allison McGeer
- Department of Microbiology, Mount Sinai Hospital, University of Toronto, Ontario
| | - Daniel S Sitar
- Departments of Pharmacology and Therapeutics, Medicine and Medical Microbiology, University of Manitoba, Winnipeg, Manitoba
| | | | - Kolbe Faron
- York Region Health Services Department, Newmarket, Ontario
| | - Pamela Orr
- Departments of Pharmacology and Therapeutics, Medicine and Medical Microbiology, University of Manitoba, Winnipeg, Manitoba
| | - Fred Y Aoki
- Departments of Pharmacology and Therapeutics, Medicine and Medical Microbiology, University of Manitoba, Winnipeg, Manitoba
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Bjørgaas M, Vik T, Sager G, Sagen E, Jorde R. Urinary excretion of adrenaline and noradrenaline during hypoglycaemic clamp in diabetic and non-diabetic adolescents. Scand J Clin Lab Invest 1997; 57:711-8. [PMID: 9458494 DOI: 10.3109/00365519709105233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The urinary excretion of non-conjugated adrenaline and noradrenaline during hypoglycaemic clamp was investigated in 16 diabetic and 15 non-diabetic adolescents. In the diabetic adolescents, the mean excretion of adrenaline was approximately nine times higher in clamp urine than in morning urine (p < 0.0001). In the non-diabetic adolescents, the mean excretion of adrenaline was 20-30 times higher in clamp urine than in morning urine (p < 0.0001). Plasma catecholamines were measured, and the area under the plasma concentration-time curve (AUC) and renal clearance of catecholamines were calculated. There was a linear correlation between the AUC and the urinary excretion of adrenaline (r = 0.57, p = 0.001) and noradrenaline (r = 0.49, p = 0.006) during the hypoglycaemic clamp. The renal clearance of adrenaline and noradrenaline did not differ between the diabetic and non-diabetic subjects. In the diabetic group, there was a positive correlation between HbA1c and the adrenaline excretion in clamp urine (r = 0.60, p = 0.015). The eight diabetic subjects with HbA1c < 10% had lower adrenaline excretion in clamp urine than the subjects with HbA1c > 10% and the non-diabetic subjects (all p values < 0.05). We conclude that there is a marked increase in urinary adrenaline excretion during hypoglycaemia in diabetic and non-diabetic adolescents. The increase in adrenaline excretion during hypoglycaemia was attenuated in the better-controlled diabetic adolescents in our study.
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Affiliation(s)
- M Bjørgaas
- Department of Clinical Chemistry, University Hospital of Trondheim, Norway
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Bertz RJ, Granneman GR. Use of in vitro and in vivo data to estimate the likelihood of metabolic pharmacokinetic interactions. Clin Pharmacokinet 1997; 32:210-58. [PMID: 9084960 DOI: 10.2165/00003088-199732030-00004] [Citation(s) in RCA: 549] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This article reviews the information available to assist pharmacokineticists in the prediction of metabolic drug interactions. Significant advances in this area have been made in the last decade, permitting the identification in early drug development of dominant cytochrome P450 (CYP) isoform(s) metabolising a particular drug as well as the ability of a drug to inhibit a specific CYP isoform. The major isoforms involved in human drug metabolism are CYP3A, CYP2D6, CYP2C, CYP1A2 and CYP2E1. Often patients are taking multiple concurrent medications, and thus an assessment of potential drug-drug interactions is imperative. A database containing information about the clearance routes for over 300 drugs from multiple therapeutic classes, including analgesics, anti-infectives, psychotropics, anticonvulsants, cancer chemotherapeutics, gastrointestinal agents, cardiovascular agents and others, was constructed to assist in the semiquantitative prediction of the magnitude of potential interactions with drugs under development. With knowledge of the in vitro inhibition constant of a drug (Ki) for a particular CYP isoform, it is theoretically possible to assess the likelihood of interactions for a drug cleared through CYP-mediated metabolism. For many agents, the CYP isoform involved in metabolism has not been identified and there is substantial uncertainty given the current knowledge base. The mathematical concepts for prediction based on competitive enzyme inhibition are reviewed in this article. These relationships become more complex if the inhibition is of a mixed competitive/noncompetitive nature. Sources of uncertainty and inaccuracy in predicting the magnitude of in vivo inhibition includes the nature and design of in vitro experiments to determine Ki, inhibitor concentration in the hepatic cytosol compared with that in plasma, prehepatic metabolism, presence of active metabolites and enzyme induction. The accurate prospective prediction of drug interactions requires rigorous attention to the details of the in vitro results, and detailed information about the pharmacokinetics and metabolism of the inhibitor and inhibited drug. With the discussion of principles and accompanying tabulation of literature data concerning the clearance of various drugs, a framework for reasonable semiquantitative predictions is offered in this article.
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Affiliation(s)
- R J Bertz
- Department of Pharmacokinetics and Biopharmaceutics, Abbott Laboratories, Abbott Park, Illinois, USA
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