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Chow SL, Bozkurt B, Baker WL, Bleske BE, Breathett K, Fonarow GC, Greenberg B, Khazanie P, Leclerc J, Morris AA, Reza N, Yancy CW. Complementary and Alternative Medicines in the Management of Heart Failure: A Scientific Statement From the American Heart Association. Circulation 2023; 147:e4-e30. [PMID: 36475715 DOI: 10.1161/cir.0000000000001110] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Complementary and alternative medicines (CAM) are commonly used across the world by diverse populations and ethnicities but remain largely unregulated. Although many CAM agents are purported to be efficacious and safe by the public, clinical evidence supporting the use of CAM in heart failure remains limited and controversial. Furthermore, health care professionals rarely inquire or document use of CAM as part of the medical record, and patients infrequently disclose their use without further prompting. The goal of this scientific statement is to summarize published efficacy and safety data for CAM and adjunctive interventional wellness approaches in heart failure. Furthermore, other important considerations such as adverse effects and drug interactions that could influence the safety of patients with heart failure are reviewed and discussed.
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Matsumoto S, Uehara S, Kamimura H, Cho N, Ikeda H, Maeda S, Kagiyama K, Miyata A, Suemizu H, Fukasawa K. Selection of the candidate compound at an early stage of new drug development: retrospective pharmacokinetic and metabolic evaluations of valsartan using common marmosets. Xenobiotica 2022; 52:613-624. [PMID: 36148579 DOI: 10.1080/00498254.2022.2127131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Shogo Matsumoto
- Drug & Discovery & Management Department, R&D Division, Meiji Seika Pharma Co., Ltd., Tokyo, Japan
| | - Shotaro Uehara
- Department of Applied Research for Laboratory Animals, Central Institute for Experimental Animals, Kawasaki, Japan
| | - Hidetaka Kamimura
- Department of Applied Research for Laboratory Animals, Central Institute for Experimental Animals, Kawasaki, Japan.,Business Promotion Department, CLEA Japan, Inc., Tokyo, Japan
| | - Naoki Cho
- Drug & Discovery & Management Department, R&D Division, Meiji Seika Pharma Co., Ltd., Tokyo, Japan
| | - Hiroshi Ikeda
- Tokyo Animal & Diet Department, CLEA Japan, Inc., Tokyo, Japan
| | - Satoshi Maeda
- Yaotsu Breeding Center, CLEA Japan, Inc., Gifu, Japan
| | | | - Atsunori Miyata
- Drug & Discovery & Management Department, R&D Division, Meiji Seika Pharma Co., Ltd., Tokyo, Japan
| | - Hiroshi Suemizu
- Department of Applied Research for Laboratory Animals, Central Institute for Experimental Animals, Kawasaki, Japan
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Wani TU, Mir KB, Fazli AA, Raza SN, Khan NA. HPMC/Carbopol based extended release gastroretentive dosage form of losartan potassium: Formulation and in vivo pharmacokinetic evaluation in rabbits. J Drug Deliv Sci Technol 2020. [DOI: 10.1016/j.jddst.2020.102006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Park J, Choi J. Role of kaempferol to increase bioavailability and pharmacokinetics of nifedipine in rats. Chin J Nat Med 2019; 17:690-7. [DOI: 10.1016/s1875-5364(19)30083-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Indexed: 11/16/2022]
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Abstract
1. This study investigates the influence of quercetin on the pharmacokinetics of losartan and its metabolite EXP3174 in rats. 2. The pharmacokinetic profiles of losartan and EXP3174 of orally administered losartan (10 mg/kg) with or without pretreatment with quercetin (20 mg/kg/day for 7 days) were investigated. Additionally, Caco-2 cell transwell model and rat liver microsome incubation experiments were also conducted to investigate its potential mechanism. 3. The results showed that when the rats were pretreated with quercetin, the Cmax (2.16 ± 0.40 vs. 1.33 ± 0.21 mg/L) and the AUC(0-t) (13.89 ± 1.22 vs. 7.34 ± 0.75 mg·h/L) of losartan increased significantly (p < .05), and while the Cmax (0.76 ± 0.09 vs. 1.14 ± 0.18 mg/L) of EXP3174 decreased significantly compared to the control (p < .05). The t1/2 of losartan was prolonged from 3.27 ± 0.45 h to 4.74 ± 0.51 h (p < .05). The results also indicated that quercetin could increase losartan absorption rate by inhibiting the activity of P-gp and decrease its metabolic stability by inhibiting the activity of CYP450 enzyme. 4. These results indicated that the herb-drug interaction between quercetin and losartan might occur when they are co-administered in rats, quercetin could increase the systemic exposure of losartan and decrease the plasma concentration of EXP3174, possibly by inhibiting the activity of P-gp or CYP450 enzyme.
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Affiliation(s)
- Qingling Zhao
- a Department of Public Health , Yidu Central Hospital of Weifang , Shandong , China
| | - Jinlan Wei
- a Department of Public Health , Yidu Central Hospital of Weifang , Shandong , China
| | - Hongying Zhang
- b Department of Obstetrics , Yidu Central Hospital of Weifang , Shandong , China
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Abstract
BACKGROUND AND OBJECTIVE Ginkgo leaf tablet (GLT) is an effective traditional Chinese multi-herbal formula, which is often combined with amlodipine for treating senile hypertension in clinic. The aim of this study was to study the pharmacokinetics of amlodipine after oral administration of amlodipine and GLT and to investigate the potential for pharmacokinetic herb-drug interactions between GLT and amlodipine in rats. METHODS A liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method was developed for quantification of amlodipine in rat plasma. The accuracy, precision, linearity, selectivity and recovery were all within an acceptable range. Male Sprague-Dawley rats were randomly assigned to two groups: amlodipine group and amlodipine + GLT group. Plasma concentrations of amlodipine were determined at the designated time points after oral administration by using the developed LC-MS/MS method, and the main pharmacokinetic parameters were calculated and compared. As ginkgolides A, ginkgolides B, bilobalide, quercetin and kaempferol were the main components of GLT, the effects of these ingredients in GLT on metabolism of amlodipine were further investigated in rat liver microsomes. RESULTS The pharmacokinetic parameters, maximum plasma concentration (C max), time to reach C max (T max), area under the concentration-time curve (AUC), area under the first moment plasma concentration-time curve (AUMC) and elimination half-life (t 1/2), of amlodipine were significantly increased in amlodipine + GLT group, which suggested that GLT may influence the pharmacokinetic behavior after oral co-administration with amlodipine. Amlodipine is metabolized by cytochrome P450 (CYP) 3A4, so it was speculated that GLT may change the pharmacokinetic parameters of amlodipine through modulating the metabolism of CYP3A4 enzymes. When ginkgolides B, bilobalide, or quercetin and amlodipine were co-incubated in the rat liver microsomes, the metabolic rate of amlodipine was prolonged to 533.1, 216.1 and 407.6 min, respectively, from 73.7 min. CONCLUSIONS These results suggested that these components in GLT inhibit the metabolism of amlodipine. So it can be speculated that the herb-drug interactions between GLT and amlodipine resulted from inhibiting the metabolism of amlodipine by GLT when they were co-administered.
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Affiliation(s)
- Rong Wang
- Department of Pharmacy, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Rd, Shanghai, 200011, China
| | - Hai Zhang
- Department of Pharmacy, Eastern Hepatobiliary Surgery Hospital, School of Pharmacy, Second Military Medical University, Shanghai, 200438, China
| | - Sen Sun
- Department of Pharmacy, Eastern Hepatobiliary Surgery Hospital, School of Pharmacy, Second Military Medical University, Shanghai, 200438, China
| | - Yuanyuan Wang
- Department of Pharmacy, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Rd, Shanghai, 200011, China
| | - Yifeng Chai
- Department of Pharmaceutical Analysis, School of Pharmacy, Second Military Medical University, Shanghai, 200433, China
| | - Yongfang Yuan
- Department of Pharmacy, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Rd, Shanghai, 200011, China.
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Nguyen HQ, Lin J, Kimoto E, Callegari E, Tse S, Obach RS. Prediction of Losartan-Active Carboxylic Acid Metabolite Exposure Following Losartan Administration Using Static and Physiologically Based Pharmacokinetic Models. J Pharm Sci 2017; 106:2758-2770. [DOI: 10.1016/j.xphs.2017.03.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 03/22/2017] [Accepted: 03/27/2017] [Indexed: 01/02/2023]
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Hu Y, Zhou X, Shi H, Shi W, Ye S, Zhang H. The effect of tripterygium glucoside tablet on pharmacokinetics of losartan and its metabolite EXP3174 in rats. Biomed Chromatogr 2017; 31. [PMID: 28299812 DOI: 10.1002/bmc.3973] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 03/04/2017] [Accepted: 03/10/2017] [Indexed: 11/12/2022]
Abstract
Losartan and tripterygium glucoside tablet (TGT) are often simultaneously used for reducing urine protein excretion in clinic. However, it is unknown whether there is potential herb-drug interaction between losartan and TGT. The aim of this study was to investigate their potential herb-drug interaction, and clarify the mechanism of the effect of TGT on the pharmacokinetics of losartan and its metabolite EXP3174 in rats. The plasma concentrations of losartan and EXP3174 were determined by LC-MS, and the main pharmacokinetic parameters were calculated. The Cmax , t1/2 and AUC(0-t) of losartan became larger after co-administration, while the Cmax and AUC(0-t) of EXP3174 became smaller, suggesting that TGT could influence the pharmacokinetics of losartan and EXP3174. The effects of TGT and its main components on the metabolic rate of losartan were further investigated in rat liver microsomes. Results indicated that TGT and its two main ingredients could decrease the metabolic rate of losartan. Therefore, it was speculated that TGT might increase the plasma concentration of losartan and decrease the concentration of EXP3174 by inhibiting the metabolism of losartan. The results could provide references for clinical medication guidance of losartan and TGT to avoid the occurrence of adverse reactions.
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Affiliation(s)
| | | | - Hui Shi
- The 118th Hospital of PLA, Wenzhou, China
| | - Wenyu Shi
- The 118th Hospital of PLA, Wenzhou, China
| | | | - Hai Zhang
- Department of Pharmacy, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
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Ezuruike U, Prieto JM. Assessment of Potential Herb-Drug Interactions among Nigerian Adults with Type-2 Diabetes. Front Pharmacol 2016; 7:248. [PMID: 27559312 PMCID: PMC4978708 DOI: 10.3389/fphar.2016.00248] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/27/2016] [Indexed: 11/29/2022] Open
Abstract
It is becoming increasingly evident that patients with diabetes do not rely only on prescription drugs for their disease management. The use of herbal medicines is one of the self-management practices adopted by these patients, often without the knowledge of their healthcare practitioners. This study assessed the potential for pharmacokinetic herb-drug interactions (HDIs) amongst Nigerian adult diabetic patients. This was done through a literature analysis of the pharmacokinetic profile of their herbal medicines and prescription drugs, based on information obtained from 112 patients with type-2 diabetes attending two secondary health care facilities in Nigeria. Fifty percent of the informants used herbal medicines alongside their prescription drugs. Worryingly, 60% of the patients taking herbal medicines did not know their identity, thus increasing the risk of unidentified HDIs. By comparing the pharmacokinetic profile of eight identified herbs taken by the patients for the management of diabetes against those of the prescription drugs, several scenarios of potential HDIs were identified and their clinical relevance is discussed. The lack of clinical predictors points toward cultural factors as the influence for herb use, making it more difficult to identify these patients and in turn monitor potential HDIs. In identifying these possible interactions, we have highlighted the need for healthcare professionals to promote a proactive monitoring of patients' use of herbal medicines.
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Affiliation(s)
- Udoamaka Ezuruike
- Department of Pharmaceutical and Biological Chemistry, Centre for Pharmacognosy and Phytotherapy, University College London School of Pharmacy London, UK
| | - Jose M Prieto
- Department of Pharmaceutical and Biological Chemistry, Centre for Pharmacognosy and Phytotherapy, University College London School of Pharmacy London, UK
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van der Hooft JJJ, Padmanabhan S, Burgess KEV, Barrett MP. Urinary antihypertensive drug metabolite screening using molecular networking coupled to high-resolution mass spectrometry fragmentation. Metabolomics 2016; 12:125. [PMID: 27471437 PMCID: PMC4932139 DOI: 10.1007/s11306-016-1064-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 04/01/2016] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Mass spectrometry is the current technique of choice in studying drug metabolism. High-resolution mass spectrometry in combination with MS/MS gas-phase experiments has the potential to contribute to rapid advances in this field. However, the data emerging from such fragmentation spectral files pose challenges to downstream analysis, given their complexity and size. OBJECTIVES This study aims to detect and visualize antihypertensive drug metabolites in untargeted metabolomics experiments based on the spectral similarity of their fragmentation spectra. Furthermore, spectral clusters of endogenous metabolites were also examined. METHODS Here we apply a molecular networking approach to seek drugs and their metabolites, in fragmentation spectra from urine derived from a cohort of 26 patients on antihypertensive therapy. The mass spectrometry data was collected on a Thermo Q-Exactive coupled to pHILIC chromatography using data dependent analysis (DDA) MS/MS gas-phase experiments. RESULTS In total, 165 separate drug metabolites were found and structurally annotated (17 by spectral matching and 122 by classification based on a clustered fragmentation pattern). The clusters could be traced to 13 drugs including the known antihypertensives verapamil, losartan and amlodipine. The molecular networking approach also generated clusters of endogenous metabolites, including carnitine derivatives, and conjugates containing glutamine, glutamate and trigonelline. CONCLUSIONS The approach offers unprecedented capability in the untargeted identification of drugs and their metabolites at the population level and has great potential to contribute to understanding stratified responses to drugs where differences in drug metabolism may determine treatment outcome.
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Affiliation(s)
| | - Sandosh Padmanabhan
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Karl E. V. Burgess
- Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Michael P. Barrett
- Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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Choi JS, Choi JS, Choi DH. Effects of licochalcone A on the bioavailability and pharmacokinetics of nifedipine in rats: possible role of intestinal CYP3A4 and P-gp inhibition by licochalcone A. Biopharm Drug Dispos 2014; 35:382-90. [PMID: 24903704 DOI: 10.1002/bdd.1905] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 04/14/2014] [Accepted: 06/02/2014] [Indexed: 12/23/2022]
Abstract
The purpose of this study was to investigate the possible effects of licochalcone A (a herbal medicine) on the pharmacokinetics of nifedipine and its main metabolite, dehydronifedipine, in rats. The pharmacokinetic parameters of nifedipine and/or dehydronifedipine were determined after oral and intravenous administration of nifedipine to rats in the absence (control) and presence of licochalcone A (0.4, 2.0 and 10 mg/kg). The effect of licochalcone A on P-glycoprotein (P-gp) and cytochrome P450 (CYP) 3A4 activity was also evaluated. Nifedipine was mainly metabolized by CYP3A4. Licochalcone A inhibited CYP3A4 enzyme activity in a concentration-dependent manner with a 50% inhibition concentration (IC50 ) of 5.9 μm. In addition, licochalcone A significantly enhanced the cellular accumulation of rhodamine-123 in MCF-7/ADR cells overexpressing P-gp. The area under the plasma concentration-time curve from time 0 to infinity (AUC) and the peak plasma concentration (Cmax ) of oral nifedipine were significantly greater and higher, respectively, with licochalcone A. The metabolite (dehydronifedipine)-parent AUC ratio (MR) in the presence of licochalcone A was significantly smaller compared with the control group. The above data could be due to an inhibition of intestinal CYP3A4 and P-gp by licochalcone A. The AUCs of intravenous nifedipine were comparable without and with licochalcone A, suggesting that inhibition of hepatic CYP3A4 and P-gp was almost negligible.
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Affiliation(s)
- Jin-Seok Choi
- College of Pharmacy, Ajou University, Suwon, Republic of Korea
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Michel MC, Foster C, Brunner HR, Liu L. A systematic comparison of the properties of clinically used angiotensin II type 1 receptor antagonists. Pharmacol Rev 2013; 65:809-48. [PMID: 23487168 DOI: 10.1124/pr.112.007278] [Citation(s) in RCA: 205] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Angiotensin II type 1 receptor antagonists (ARBs) have become an important drug class in the treatment of hypertension and heart failure and the protection from diabetic nephropathy. Eight ARBs are clinically available [azilsartan, candesartan, eprosartan, irbesartan, losartan, olmesartan, telmisartan, valsartan]. Azilsartan (in some countries), candesartan, and olmesartan are orally administered as prodrugs, whereas the blocking action of some is mediated through active metabolites. On the basis of their chemical structures, ARBs use different binding pockets in the receptor, which are associated with differences in dissociation times and, in most cases, apparently insurmountable antagonism. The physicochemical differences between ARBs also manifest in different tissue penetration, including passage through the blood-brain barrier. Differences in binding mode and tissue penetration are also associated with differences in pharmacokinetic profile, particularly duration of action. Although generally highly specific for angiotensin II type 1 receptors, some ARBs, particularly telmisartan, are partial agonists at peroxisome proliferator-activated receptor-γ. All of these properties are comprehensively reviewed in this article. Although there is general consensus that a continuous receptor blockade over a 24-hour period is desirable, the clinical relevance of other pharmacological differences between individual ARBs remains to be assessed.
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Affiliation(s)
- Martin C Michel
- Department of Clinical Development & Medical Affairs, Boehringer Ingelheim, 55216 Ingelheim, Germany.
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Mertens-Talcott SU, Zadezensky I, De Castro WV, Derendorf H, Butterweck V. Grapefruit-Drug Interactions: Can Interactions With Drugs Be Avoided? J Clin Pharmacol 2013; 46:1390-416. [PMID: 17101740 DOI: 10.1177/0091270006294277] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Grapefruit is rich in flavonoids, which have been demonstrated to have a preventive influence on many chronic diseases, such as cancer and cardiovascular disease. However, since the early 1990s, the potential health benefits of grapefruit have been overshadowed by the possible risk of interactions between drugs and grapefruit and grapefruit juice. Several drugs interacting with grapefruit are known in different drug classes, such as HMG-CoA reductase inhibitors, calcium antagonists, and immunosuppressives. Currently known mechanisms of interaction include the inhibition of cytochrome P450 as a major mechanism, but potential interactions with P-glycoprotein and organic anion transporters have also been reported. This review is designed to provide a comprehensive summary of underlying mechanisms of interaction and human clinical trials performed in the area of grapefruit drug interactions and to point out possible replacements for drugs with a high potential for interactions.
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Affiliation(s)
- S U Mertens-Talcott
- Department of Pharmaceutics, Center for Food Drug Interaction Research and Education, University of Florida, Gainesville, FL 32610-0494, USA
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Isoherranen N, Lutz JD, Chung SP, Hachad H, Levy RH, Ragueneau-Majlessi I. Importance of multi-p450 inhibition in drug-drug interactions: evaluation of incidence, inhibition magnitude, and prediction from in vitro data. Chem Res Toxicol 2012; 25:2285-300. [PMID: 22823924 PMCID: PMC3502654 DOI: 10.1021/tx300192g] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Drugs that are mainly cleared by a single enzyme are considered more sensitive to drug-drug interactions (DDIs) than drugs cleared by multiple pathways. However, whether this is true when a drug cleared by multiple pathways is coadministered with an inhibitor of multiple P450 enzymes (multi-P450 inhibition) is not known. Mathematically, simultaneous equipotent inhibition of two elimination pathways that each contribute half of the drug clearance is equal to equipotent inhibition of a single pathway that clears the drug. However, simultaneous strong or moderate inhibition of two pathways by a single inhibitor is perceived as an unlikely scenario. The aim of this study was (i) to identify P450 inhibitors currently in clinical use that can inhibit more than one clearance pathway of an object drug in vivo and (ii) to evaluate the magnitude and predictability of DDIs caused by these multi-P450 inhibitors. Multi-P450 inhibitors were identified using the Metabolism and Transport Drug Interaction Database. A total of 38 multi-P450 inhibitors, defined as inhibitors that increased the AUC or decreased the clearance of probes of two or more P450s, were identified. Seventeen (45%) multi-P450 inhibitors were strong inhibitors of at least one P450, and an additional 12 (32%) were moderate inhibitors of one or more P450s. Only one inhibitor (fluvoxamine) was a strong inhibitor of more than one enzyme. Fifteen of the multi-P450 inhibitors also inhibit drug transporters in vivo, but such data are lacking on many of the inhibitors. Inhibition of multiple P450 enzymes by a single inhibitor resulted in significant (>2-fold) clinical DDIs with drugs that are cleared by multiple pathways such as imipramine and diazepam, while strong P450 inhibitors resulted in only weak DDIs with these object drugs. The magnitude of the DDIs between multi-P450 inhibitors and diazepam, imipramine, and omeprazole could be predicted using in vitro data with similar accuracy as probe substrate studies with the same inhibitors. The results of this study suggest that inhibition of multiple clearance pathways in vivo is clinically relevant, and the risk of DDIs with object drugs may be best evaluated in studies using multi-P450 inhibitors.
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Affiliation(s)
- Nina Isoherranen
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Box 357610, Seattle, WA 98195, USA.
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Yang SH, Cho YA, Choi JS. Effects of ticlopidine on pharmacokinetics of losartan and its main metabolite EXP-3174 in rats. Acta Pharmacol Sin 2011; 32:967-72. [PMID: 21666702 DOI: 10.1038/aps.2011.32] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
AIM Losartan and antiplatelet agent ticlopidine can be prescribed concomitantly for prevention or therapy of cardiovascular diseases. Hence, the effects of ticlopidine on the pharmacokinetics of losartan and its active metabolite EXP-3174 were evaluated in rats. METHODS Ticlopidine (4 or 10 mg/kg po) was administered 30 min before administration of losartan (9 mg/kg po or 3 mg/kg iv). The activity of human CYP2C9 and 3A4 were measured using the CYP inhibition assay kit. The activity of P-gp was evaluated using rhodamine-123 retention assay in MCF-7/ADR cells. RESULTS Ticlopidine (10 mg/kg) significantly increased the areas under the plasma concentration-time curves (AUCs) and peak plasma concentration (C(max)) of oral losartan (9 mg/kg), as well as the AUCs of the active metabolite EXP-3174. Ticlopidine (10 mg/kg) did not significantly change the pharmacokinetics of intravenous losartan (3 mg/kg). Ticlopidine inhibited CYP2C9 and 3A4 with IC₅₀ values of 26.0 and 32.3 μmol/L, respectively. The relative cellular uptake of rhodamine-123 was unchanged. CONCLUSION The significant increase in the AUC of losartan (9 mg/kg) by ticlopidine (10 mg/kg) could be attributed to the inhibition of CYP2C9- and 3A4-mediated losartan metabolism in small intestine and/or in liver. The inhibition of P-gp in small intestine and reduction of renal elimination of losartan by ticlopidine are unlikely to be causal factors.
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Abstract
Grapefruit juice and grapefruit product consumption have potential health benefits; however, their intake is also associated with interactions with certain drugs, including calcium channel blockers, immunosuppressants and antihistamines. The primary mechanism through which interactions are mediated is mechanism-based intestinal cytochrome P450 3A4 inhibition by furanocoumarins resulting in increased bioavailability of administered medications that are substrates. Grapefruit products have also been associated with interactions with P-glycoprotein (P-gp) and uptake transporters (e.g. organic anion-transporting polypeptides [OATPs]). Polyphenolic compounds such as flavonoids have been proposed as the causative agents of the P-gp and OATP interactions. The mechanisms and magnitudes of the interactions can be influenced by the concentrations of furanocoumarins and flavonoids in the grapefruit product, the volume of juice consumed, and the inherent variability of specific enzymes and transporter components in humans. It is therefore challenging to predict the extent of grapefruit product-drug interactions and to compare available in vitro and in vivo data. The clinical significance of such interactions also depends on the disposition and toxicity profile of the drug being administered. The aim of this review is to outline the mechanisms of grapefruit-drug interactions and present a comprehensive summary of those agents affected and whether they are likely to be of clinical relevance.
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Affiliation(s)
- Kay Seden
- NIHR Biomedical Research Centre, Royal Liverpool and Broadgreen University Hospital Trust, Liverpool, UK.
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Abstract
INTRODUCTION Since their initial discovery in 1989, grapefruit juice (GFJ)-drug interactions have received extensive interest from the scientific, medical, regulatory and lay communities. Although knowledge regarding the effects of GFJ on drug disposition continues to expand, the list of drugs studied in the clinical setting remains relatively limited. AREAS COVERED This article reviews the in vitro effects of GFJ and its constituents on the activity of CYP enzymes, organic anion-transporting polypeptides (OATPs), P-glycoprotein, esterases and sulfotransferases. The translational applicability of the in vitro findings to the clinical setting is discussed for each drug metabolizing enzyme and transporter. Reported AUC ratios for available GFJ-drug interaction studies are also provided. Relevant investigations were identified by searching the PubMed electronic database from 1989 to 2010. EXPERT OPINION GFJ increases the bioavailability of some orally administered drugs that are metabolized by CYP3A and normally undergo extensive presystemic extraction. In addition, GFJ can decrease the oral absorption of a few drugs that rely on OATPs in the gastrointestinal tract for their uptake. The number of drugs shown to interact with GFJ in vitro is far greater than the number of clinically relevant GFJ-drug interactions. For the majority of patients, complete avoidance of GFJ is unwarranted.
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Affiliation(s)
- Michael J Hanley
- Tufts University School of Medicine, Program in Pharmacology and Experimental Therapeutics, 136 Harrison Avenue, Boston, MA 02111, USA
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Owira PM, Ojewole JA. The grapefruit: an old wine in a new glass? Metabolic and cardiovascular perspectives. Cardiovasc J Afr 2010; 21:280-5. [PMID: 20972517 PMCID: PMC3721883 DOI: 10.5830/cvja-2010-012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2009] [Accepted: 03/10/2010] [Indexed: 01/11/2023] Open
Abstract
Grapefruit is a popular, tasty and nutritive fruit enjoyed globally. Biomedical evidence in the last 10 years has, however, shown that consumption of grapefruit or its juice is associated with drug interactions, which, in some cases, have been fatal. Grapefruit-induced drug interactions are unique in that the cytochrome P450 enzyme CYP3A4, which metabolises over 60% of commonly prescribed drugs as well as other drug transporter proteins such as P-glycoprotein and organic cation transporter proteins, which are all expressed in the intestines, are involved. However, the extent to which grapefruit-drug interactions impact on clinical settings has not been fully determined, probably because many cases are not reported. It has recently emerged that grapefruit, by virtue of its rich flavonoid content, is beneficial in the management of degenerative diseases such as diabetes and cardiovascular disorders. This potentially explosive subject is reviewed here.
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Affiliation(s)
- P M Owira
- Department of Pharmacology, University of KwaZulu-Natal, Durban, South Africa.
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Choi DH, Li C, Choi JS. Effects of myricetin, an antioxidant, on the pharmacokinetics of losartan and its active metabolite, EXP-3174, in rats: possible role of cytochrome P450 3A4, cytochrome P450 2C9 and P-glycoprotein inhibition by myricetin. J Pharm Pharmacol 2010; 62:908-14. [DOI: 10.1211/jpp.62.07.0012] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Abstract
Introduction. The concentration of many orally given medications may be
affected by grapefruit or grapefruit juice consumption. It may result in
numerous harmful effects. Interaction of grapefruit with drugs. Taking only
one cup of juice may induce interactions with different drugs even during the
period of a few days. The effect is induced by suppression of cytochrome P450
isoenzyme CYP3A4 in the intestinal wall. The Latin name of grapefruit, Citrus
paradisi, is quite opposite to the effects which could be induced by taking
grapefruit and some medications at the same time. It is necessary to avoid
taking grapefruit with the drugs whose pharmacokinetics could be altered by
the active principles found in that fruit. Discussion. The coloured
grapefruit contains less furanocoumarins, but there is no difference in
induction and intensity of pharmacokinetic interaction with drugs related to
its colour. Other citrus fruits (orange, lemon) do not have such effects, but
some other fruits (pomegranate, stella fruit, banpeiyu, hassaku,
takaoka-buntan and kinkan) exert inhibitory effects on the activity of
cytochrome P450 isoenzyme.
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Affiliation(s)
- Zoran Bojanic
- Medicinski fakultet, Institut za farmakologiju i toksikologiju, Niš
| | - Novica Bojanic
- Medicinski fakultet, Institut za farmakologiju i toksikologiju, Niš
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Wang G, Xiao CQ, Li Z, Guo D, Chen Y, Fan L, Qian RH, Peng XJ, Hu DL, Zhou HH. Effect of soy extract administration on losartan pharmacokinetics in healthy female volunteers. Ann Pharmacother 2009; 43:1045-9. [PMID: 19458107 DOI: 10.1345/aph.1l690] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND osartan is metabolized by CYP2C9 and CYP3A4 to an active metabolite, E-3174, which has greater antihypertensive activity than the parent compound. Soy extract has been shown to be an activator of CYP2C9 and CYP3A4 in vitro. Coadministration of soy extract and losartan may therefore alter the pharmacokinetics of losartan and E-3174. OBJECTIVE To determine whether, when losartan was used in combination with soy extract, a significant pharmacokinetic interaction would be observed in healthy female volunteers. METHODS Eighteen healthy Chinese female volunteers were recruited. In an open-label, 2-phase study, losartan 50 mg was given to each subject, with and without soy extract. Plasma concentrations of losartan and E-3174 were determined by liquid chromatography-tandem mass spectrometry for 12 and 24 hours, respectively. On day 8 through day 21 of the study, following a 7-day washout period, each subject consumed two 1000-mg Genistein Soy Complex tablets orally after meals, twice daily, for 14 days. On day 22, all volunteers received losartan 50 mg and blood samples were collected again. RESULTS All subjects completed the study, without adverse drug effects. Over the 14-day pretreatment period, soy extract did not significantly influence the pharmacokinetics of losartan or E-3174. The ratio of the area under the curve of the drug and metabolite after losartan administration, with and without soy extract ingestion, was 0.21 +/- 0.05 and 0.23 +/- 0.05 (mean +/- SD), respectively. The difference was not statistically significant (p = 0.22). CONCLUSIONS Our data indicate that a significant interaction between soy extract and losartan is unlikely to occur in females.
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Affiliation(s)
- Guo Wang
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University, Changsha, Hunan, China
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Prasaja B, Sasongko L, Harahap Y, Hardiyanti, Lusthom W, Grigg M. Simultaneous quantification of losartan and active metabolite in human plasma by liquid chromatography–tandem mass spectrometry using irbesartan as internal standard. J Pharm Biomed Anal 2009; 49:862-7. [DOI: 10.1016/j.jpba.2009.01.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Revised: 01/08/2009] [Accepted: 01/08/2009] [Indexed: 11/20/2022]
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Abstract
Losartan is the first orally available angiotensin-receptor antagonist without agonist properties. Following oral administration, losartan is rapidly absorbed, reaching maximum concentrations 1-2 hours post-administration. After oral administration approximately 14% of a losartan dose is converted to the pharmacologically active E 3174 metabolite. E 3174 is 10- to 40-fold more potent than its parent compound and its estimated terminal half-life ranges from 6 to 9 hours. The pharmacokinetics of losartan and E 3174 are linear, dose-proportional and do not substantially change with repetitive administration. The recommended dosage of losartan 50 mg/day can be administered without regard to food. There are no clinically significant effects of age, sex or race on the pharmacokinetics of losartan, and no dosage adjustment is necessary in patients with mild hepatic impairment or various degrees of renal insufficiency. Losartan, or its E 3174 metabolite, is not removed during haemodialysis. The major metabolic pathway for losartan is by the cytochrome P450 (CYP) 3A4, 2C9 and 2C10 isoenzymes. Overall, losartan has a favorable drug-drug interaction profile, as evidenced by the lack of clinically relevant interactions between this drug and a range of inhibitors and stimulators of the CYP450 system. Losartan does not have a drug-drug interaction with hydrochlorothiazide, warfarin or digoxin. Losartan should be avoided in pregnancy, as is the case with all other angiotensin-receptor antagonists. When given in the second and third trimester of pregnancy, losartan is often associated with serious fetal toxicity. Losartan is a competitive antagonist that causes a parallel rightward shift of the concentration-contractile response curve to angiotensin-II, while E 3174 is a noncompetitive "insurmountable" antagonist of angiotensin-II. The maximum recommended daily dose of losartan is 100mg, which can be given as a once-daily dose or by splitting the same total daily dose into two doses. Losartan reduces blood pressure comparably to other angiotensin-receptor antagonists. Losartan has been extensively studied relative to end-organ protection, with studies having been conducted in diabetic nephropathy, heart failure, post-myocardial infarction and hypertensive patients with left ventricular hypertrophy. The results of these studies have been sufficiently positive to support a more widespread use of angiotensin-receptor antagonists in the setting of various end-organ diseases. Losartan, like other angiotensin-receptor antagonists, is devoid of significant adverse effects.
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Affiliation(s)
- Domenic A Sica
- Division of Nephrology, Medical College of Virginia, Virginia Commonwealth University, PO Box 980160, Richmond, VA 23298, USA.
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Saito M, Hirata-Koizumi M, Matsumoto M, Urano T, Hasegawa R. Undesirable effects of citrus juice on the pharmacokinetics of drugs: focus on recent studies. Drug Saf 2005; 28:677-94. [PMID: 16048354 DOI: 10.2165/00002018-200528080-00003] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
It is well known that intake of grapefruit juice affects the pharmacokinetics of various kinds of drugs. It has been reported that other citrus juices also interact with certain drugs. To re-evaluate citrus juice-drug interactions based on currently available evidence, a literature search was conducted for new and updated information since the grapefruit juice-drug interaction was last reviewed in 1998. MEDLINE (1998-October 2004) was accessed and more than 200 reports were found. The effects of grapefruit juice ingestion on the pharmacokinetics of orally administered drugs have been reported for 40 drugs since the reviews published in 1998. Increases in either area under the concentration-time curve (AUC) or maximum plasma concentration (C(max)) were found with 34 of these, the major mechanism being considered to be inactivation of intestinal cytochrome P450 3A4, a so-called mechanism-based inhibition. Although recent reports point to the inhibitory effects of grapefruit juice on the function of P-glycoprotein, which transports substrates from enterocytes back into the lumen, the contribution to the bioavailability of drugs that are substrates of P-glycoprotein has not been established yet. Dramatic decreases in AUC and C(max) for two drugs in association with grapefruit juice ingestion has been reported and, in these cases, inhibitory effects on organic anion transporting polypeptide, which mediates absorption from the intestinal lumen to enterocytes, might be involved. Other citrus juices such as Seville (sour) orange juice and commonly ingested varieties of orange juice also showed significant effects on the AUC and C(max) of some drugs. Although the situation is complex and uncertainties remain, we recommend that patients avoid citrus juice intake while taking medications and that healthcare providers advise against citrus juice intake in this setting until any interactions with subject drugs can be clarified in clinical studies.
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Affiliation(s)
- Mitsuo Saito
- Division of Medicinal Safety Science, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
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Abstract
Hypertension is a major risk factor for the development of cardiovascular disease. Numerous placebo-controlled trials have demonstrated that treatment of hypertension results in substantial reduction of hypertension-related vascular events. The benefit of specific therapies beyond their effect on blood pressure is well established. Losartan is an orally-active, selective, nonpeptide, angiotensin II type 1-receptor antagonist (ARB), and it was the first in this class to be marketed. Several large-scale clinical trials have demonstrated that losartan and other ARBs have benefits in preventing cardiovascular disease. The Losartan Intervention For End point reduction in hypertension (LIFE) study demonstrated improved outcomes with losartan as compared with atenolol-based therapies in hypertensive patients with left ventricular hypertrophy, mainly because of stroke prevention. The Reduction of End points in Non-insulin-dependent diabetes mellitus with the Angiotensin II Antagonist Losartan (RENAAL) study demonstrated that losartan prevented the progression of diabetic nephropathy. In this review, evidence from these and other clinical trials with losartan shall be discussed. The pharmacodynamic and pharmacokinetic properties of losartan are described to explain its mechanisms of action. Among the ARB class, losartan possesses certain unique properties, which may enhance its cardiovascular protective effects. These include an increase of urinary uric acid excretion and antiatherothrombotic properties. Potential future roles for losartan and other ARBs shall be discussed, in addition to emphasizing areas in which evidence is currently lacking or indecisive, including head-to-head comparisons of ARBs and the effects of combining an ARB with angiotensin-converting-enzyme inhibitors.
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Affiliation(s)
- Sanne de Vogel
- Veterans Affairs Medical Center, 151 E, 50 Irving Street NW, Washington DC, 20422, USA
| | - Ewout J Hoorn
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Vasilios Papademetriou
- Georgetown University School of Medicine, Hypertension Research Clinic, Veterans Affairs Medical Center, Washington DC, USA
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Berellini G, Cruciani G, Mannhold R. Pharmacophore, Drug Metabolism, and Pharmacokinetics Models on Non-Peptide AT1, AT2, and AT1/AT2Angiotensin II Receptor Antagonists. J Med Chem 2005; 48:4389-99. [PMID: 15974591 DOI: 10.1021/jm049024x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
About 20 non-peptide angiotensin II receptor antagonists are in various stages of clinical development. Different modeling approaches were used to predict the pharmacophoric requirements for AT(1) (angiotensin II receptor subtype 1) affinity. However, to our knowledge, none was used to predict both the selectivity toward AT(1) and AT(2) (angiotensin II receptor subtype 2) receptor subtypes. In this paper, partial least squares discriminant analysis is applied to derive the chemical features guiding AT(1) and AT(2) selectivity or mixed AT(1)/AT(2) receptor binding. The method can be used to modulate AT(1) versus AT(2) selectivity. Concerns that unopposed stimulation of the AT(2) receptor might produce adverse effects initiated a search for new balanced antagonists. Moreover, it can serve as a fast filtering procedure in database searches. Finally, some relevant pharmacokinetics and metabolic properties of the database of 53 compounds are calculated using the VolSurf and MetaSite software to allow the simultaneous characterization of pharmacodynamic and pharmacokinetics properties of the chemical space of angiotensin II receptor antagonists.
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Affiliation(s)
- Giuliano Berellini
- Laboratory for Chemometrics and Cheminformatics, Department of Chemistry, University of Perugia, Via Elce di sotto 10, I-06123 Perugia, Italy
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Tamimi JJI, Salem II, Mahmood Alam S, Zaman Q, Dham R. Comparative pharmacokinetics of two tablet formulations of Losartan: bioequivalence assessment. Biopharm Drug Dispos 2005; 26:205-10. [PMID: 15906418 DOI: 10.1002/bdd.448] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The pharmacokinetic profiles of two brands of losartan 50 mg tablets were compared in 24 healthy adult volunteers after a single oral dose in a randomized cross-over study. The study was conducted at the ACDIMA Center for Bioequivalence & Pharmaceutical Studies, Amman, Jordan. The reference (Cozaar, MSD, The Netherlands) and test (Blosart, Julphar, UAE) products were administered to fasting volunteers. Blood samples were collected at specified time intervals, and the plasma separated and analysed for losartan and its active metabolite (losartan carboxylic acid) using a validated HPLC method with fluorescence detection. Pharmacokinetic parameters AUC(0-t), AUC(0-alpha), C(max), T(max), T(1/2), elimination rate constant, MRT, Cl/F and Vss/F were determined from plasma concentration-time profiles of both formulations and found to be in good agreement with reported values. Three parameters (AUC(0-t), AUC(0-alpha), and C(max)) were compared statistically to evaluate the bioequivalence between the two brands, using statistical modules recommended by the FDA. Analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals fell within the acceptable range (80%-125%) for bioequivalence. Based on these statistical inferences it was concluded that the two formulations exhibited comparable pharmacokinetic profiles and that Julphar's Blosart is bioequivalent to Cozaar of MSD, The Netherlands.
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Affiliation(s)
- J J I Tamimi
- ACDIMA Center for Bioequivalence & Pharmaceutical Studies, Amman, Jordan
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Abstract
P-glycoprotein (Pgp) is a 170 kDa phosphorylated glycoprotein encoded by human MDR1 gene. It is responsible for the systemic disposition of numerous structurally and pharmacologically unrelated lipophilic and amphipathic drugs, carcinogens, toxins, and other xenobiotics in many organs, such as the intestine, liver, kidney, and brain. Like cytochrome P450s (CYP3A4), Pgp is vulnerable to inhibition, activation, or induction by herbal constituents. This was demonstrated by using an ATPase assay, purified Pgp protein or intact Pgp-expressing cells, and proper probe substrates and inhibitors. Curcumin, ginsenosides, piperine, some catechins from green tea, and silymarin from milk thistle were found to be inhibitors of Pgp, while some catechins from green tea increased Pgp-mediated drug transport by heterotropic allosteric mechanism, and St. John's wort induced the intestinal expression of Pgp in vitro and in vivo. Some components (e.g., bergamottin and quercetin) from grapefruit juice were reported to modulate Pgp activity. Many of these herbal constituents, in particular flavonoids, were reported to modulate Pgp by directly interacting with the vicinal ATP-binding site, the steroid-binding site, or the substrate-binding site. Some herbal constituents (e.g., hyperforin and kava) were shown to activate pregnane X receptor, an orphan nuclear receptor acting as a key regulator of MDR1 and many other genes. The inhibition of Pgp by herbal constituents may provide a novel approach for reversing multidrug resistance in tumor cells, whereas the stimulation of Pgp expression or activity has implication for chemoprotective enhancement by herbal medicines. Certain natural flavonols (e.g., kaempferol, quercetin, and galangin) are potent stimulators of the Pgp-mediated efflux of 7,12-dimethylbenz(a)-anthracene (a carcinogen). The modulation of Pgp activity and expression by these herb constituents may result in altered absorption and bioavailability of drugs that are Pgp substrates. This is exemplified by increased oral bioavailability of phenytoin and rifampin by piperine and decreased bioavailability of indinavir, tacrolimus, cyclosporine, digoxin, and fexofenadine by coadministered St. John's wort. However, many of these drugs are also substrates of CYP3A4. Thus, the modulation of intestinal Pgp and CYP3A4 represents an important mechanism for many clinically important herb-drug interactions. Further studies are needed to explore the relative role of Pgp and CYP3A4 modulation by herbs and the mechanism for the interplay of these two important proteins in herb-drug interactions.
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Affiliation(s)
- Shufeng Zhou
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore.
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Abstract
Today, the lifetime risk of patients aged 55-65 years to receive antihypertensive drugs approaches 60%. Yet, recent trials suggest that hypertension is not adequately controlled in the majority of patients. The prevalence of hypertension increases with advancing age, as does the prevalence of comorbid conditions and the total number of medications taken. Multi-drug therapy, advancing age and comorbid conditions are also key risk factors for adverse drug reactions and drug interactions. In this review, the authors evaluate the most frequently used antihypertensive drugs (diuretics, beta-adrenergic blockers, angiotensin-converting enzyme inhibitors, calcium channel blockers, angiotensin II receptor Type 1 blockers and alpha-adrenergic blockers) with special reference to pharmacodynamic and pharmacokinetic drug interactions. As the spectrum of drugs prescribed is constantly changing, safety yesterday does not imply safety today and safety today does not imply safety tomorrow. Furthermore, therapeutic efficacy should not be neglected over concerns regarding drug interactions. Many patients are at risk of clinically relevant drug interactions involving antihypertensive drugs but, presently, even more patients may be at risk of suffering from the consequences of their inadequately treated hypertension. In this respect, the authors discuss controversial viewpoints on the overall clinical relevance of drug interactions occurring at the level of cytochrome P450 metabolism.
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Affiliation(s)
- Renke Maas
- Institut für Experimentelle und Klinische Pharmakologie, Universitätsklinikum HamburgEppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
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Abstract
Grapefruit juice can alter oral drug pharmacokinetics by different mechanisms. Irreversible inactivation of intestinal cytochrome P450 (CYP) 3A4 is produced by commercial grapefruit juice given as a single normal amount (e.g. 200-300 mL) or by whole fresh fruit segments. As a result, presystemic metabolism is reduced and oral drug bioavailability increased. Enhanced oral drug bioavailability can occur 24 hours after juice consumption. Inhibition of P-glycoprotein (P-gp) is a possible mechanism that increases oral drug bioavailability by reducing intestinal and/or hepatic efflux transport. Recently, inhibition of organic anion transporting polypeptides by grapefruit juice was observed in vitro; intestinal uptake transport appeared decreased as oral drug bioavailability was reduced. Numerous medications used in the prevention or treatment of coronary artery disease and its complications have been observed or are predicted to interact with grapefruit juice. Such interactions may increase the risk of rhabdomyolysis when dyslipidemia is treated with the HMG-CoA reductase inhibitors atorvastatin, lovastatin, or simvastatin. Potential alternative agents are pravastatin, fluvastatin, or rosuvastatin. Such interactions might also cause excessive vasodilatation when hypertension is managed with the dihydropyridines felodipine, nicardipine, nifedipine, nisoldipine, or nitrendipine. An alternative agent could be amlodipine. In contrast, the therapeutic effect of the angiotensin II type 1 receptor antagonist losartan may be reduced by grapefruit juice. Grapefruit juice interacting with the antidiabetic agent repaglinide may cause hypoglycemia, and interaction with the appetite suppressant sibutramine may cause elevated BP and HR. In angina pectoris, administration of grapefruit juice could result in atrioventricular conduction disorders with verapamil or attenuated antiplatelet activity with clopidrogel. Grapefruit juice may enhance drug toxicity for antiarrhythmic agents such as amiodarone, quinidine, disopyramide, or propafenone, and for the congestive heart failure drug, carvediol. Some drugs for the treatment of peripheral or central vascular disease also have the potential to interact with grapefruit juice. Interaction with sildenafil, tadalafil, or vardenafil for erectile dysfunction, may cause serious systemic vasodilatation especially when combined with a nitrate. Interaction between ergotamine for migraine and grapefruit juice may cause gangrene or stroke. In stroke, interaction with nimodipine may cause systemic hypotension. If a drug has low inherent oral bioavailability from presystemic metabolism by CYP3A4 or efflux transport by P-gp and the potential to produce serious overdose toxicity, avoidance of grapefruit juice entirely during pharmacotherapy appears mandatory. Although altered drug response is variable among individuals, the outcome is difficult to predict and avoiding the combination will guarantee toxicity is prevented. The elderly are at particular risk, as they are often prescribed medications and frequently consume grapefruit juice.
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Affiliation(s)
- David G Bailey
- Department of Medicine and Lawson Health Research Institute, London Health Sciences Centre, London, Ontario, Canada.
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Abstract
The ever-increasing introduction of new therapeutic agents means that the potential for drug interactions is likely to escalate. Numerous different classes of drugs are currently used to treat hypertension. The angiotensin receptor blockers offer one of the newest approaches to the management of patients with high blood pressure. Compared with other classes of antihypertensive agents, the angiotensin receptor blockers appear overall to have a low potential for drug interactions, but variations within the class have been detected. Losartan and irbesartan have a greater affinity for cytochrome p450 (CYP) isoenzymes and, thus, are more likely to be implicated in drug interactions. There is pharmacokinetic evidence to suggest that such interactions could have a clinical impact. Candesartan cilexetil, valsartan and eprosartan have variable but generally modest affinity and telmisartan has no affinity for any of the CYP isoenzymes. In vitro studies and pharmacokinetic/pharmacodynamic evaluation can provide evidence for some interactions, but only a relatively small number of drug combinations are usually studied in this way. The absence of any pharmacokinetic evidence of drug interaction, however, should not lead to complacency. Patients should be made aware of possible interactions, especially involving the concurrent use of over-the-counter products, and it may be prudent for all patients receiving antihypertensive treatment to be monitored for possible drug interactions at their regular check-ups. The physician can help by prescribing agents with a low potential for interaction, such as angiotensin receptor blockers.
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Affiliation(s)
- Thomas Unger
- Institute of Pharmacology and Toxicology, Charité Hospital, Humboldt University at Berlin, Berlin, Germany
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Affiliation(s)
- Boris Schmidt
- Clemens Schöpf Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Petersenstrasse 22, Germany.
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