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Laureen A Lammers, Roos Achterbergh, Marcel C M Pistorius, Yuma Bijleveld, Emmely M de Vries, Anita Boelen, Heinz-Josef Klümpen, Johannes A Romijn, RonA A Mathôt
BACKGROUND: The metabolic activity of P450 enzymes in vivo can be determined by using selective probe drugs. The simultaneous administration of multiple CYP-specific probe drugs is commonly referred to as the "cocktail approach." Disadvantages of a cocktail are large volumes of samples required for analysis and time-consuming analyses. The aim of this study was to develop and validate a simplified but sensitive method for the simultaneous quantification of five probe drugs (caffeine (CYP1A2), metoprolol (CYP2D6), midazolam (CYP3A4), omeprazole (CYP2C19), and S-warfarin (CYP2C9)) in a previously validated cocktail using an LC-MS/MS method...
October 19, 2016: Therapeutic Drug Monitoring
A Kenneth MacLeod, Lesley A McLaughlin, Colin J Henderson, C Roland Wolf
Tamoxifen is an oestrogen-receptor (ER) antagonist used in the treatment of breast cancer. It is a pro-drug, converted by several P450 enzymes to a primary metabolite, N-desmethyltamoxifen (NDT), which is then further modified by CYP2D6 to a pharmacologically potent secondary metabolite, 4-hydroxy-N-desmethyltamoxifen (endoxifen). Anti-depressants (ADs), which are often co-prescribed to patients receiving tamoxifen, are also metabolised by CYP2D6 and evidence suggests that a drug-drug interaction (DDI) between these agents adversely affects the outcome of tamoxifen therapy by inhibiting endoxifen formation...
October 18, 2016: Drug Metabolism and Disposition: the Biological Fate of Chemicals
Weiwei Zeng, Tanya Chu, Miao Hu, Alice Kong, Brian Tomlinson
OBJECTIVE: The blood pressure (BP) response to antihypertensive drugs varies considerably between different patients. The response to some beta-blockers has been associated with polymorphisms in the beta1-adrenergic receptor (ADRB1) or cytochrome P450 2D6 (CYP2D6) genes. We examined the effects of common polymorphisms in ADRB1 and CYP2D6 on the response to bisoprolol in 100 Chinese patients. DESIGN AND METHOD: Chinese patients with primary hypertension with sitting clinic systolic BP (SBP) 140-169 mmHg and/or diastolic BP (DBP) 90-109 mmHg after placebo run-in were treated with open-label bisoprolol 2...
September 2016: Journal of Hypertension
Young Ho Lee, Sang-Cheol Bae
OBJECTIVE: This study aimed to explore whether functional CYP2D6 polymorphisms are associated with susceptibility to autoimmune diseases. METHODS: A meta-analysis was conducted on associations between autoimmune diseases and functional CYP2D6*4 1934 A/G and *3 polymorphisms and CYP2D6 phenotypes. RESULTS: Twelve studies with 1,472 patients and 3,328 controls were included. Autoimmune disease and the CYP2D6 1934 A allele were significantly associated in the overall group, consistent with the Hardy-Weinberg equilibrium (OR = 1...
October 17, 2016: Immunological Investigations
Frank F Vincenzi, Philippe Lunetta
While SCUBA diving, a 44-year-old Caucasian patient had an abnormal cardiac rhythm, presumably Torsade de Pointes (TdP), during the initial descent to depth. Upon surfacing, she developed ventricular fibrillation and died. The patient had been treated for mild depression for nearly a year with citalopram 60 mg per day, a drug known to cause prolonged QT interval. She had also been treated with two potentially hepatotoxic drugs. Liver impairment causes selective loss of cytochrome P450 (CYP) 2C19 activity, the major pathway for metabolism of citalopram...
December 2015: Drug Saf Case Rep
Dal-Sik Kim, Yunjeong Kim, Ji-Young Jeon, Min-Gul Kim
BACKGROUND: We evaluated the drug interaction profile of Red Ginseng (RG) with respect to the activities of major cytochrome P450 (CYP) enzymes and the drug transporter P-glycoprotein (P-gp) in healthy Korean volunteers. METHODS: This article describes an open-label, crossover study. CYP probe cocktail drugs, caffeine, losartan, dextromethorphan, omeprazole, midazolam, and fexofenadine were administered before and after RG supplementation for 2 wk. Plasma samples were collected, and tolerability was assessed...
October 2016: Journal of Ginseng Research
Lisbeth Patteet, Vincent Haufroid, Kristof Maudens, Bernard Sabbe, Manuel Morrens, Hugo Neels
No abstract text is available yet for this article.
October 13, 2016: European Journal of Clinical Pharmacology
Edward C Lauterbach
Dextromethorphan (DM) may have ketamine-like rapid-acting, treatment-resistant, and conventional antidepressant effects.(1,2) This reports our initial experience with DM in unipolar Major Depressive Disorder (MDD). A patient with treatment-resistant MDD (failing adequate trials of citalopram and vortioxetine) with loss of antidepressant response (to fluoxetine and bupropion) twice experienced a rapid-acting antidepressant effect within 48 hours of DM administration and lasting 7 days, sustained up to 20 days with daily administration, then gradually developing labile loss of antidepressant response over the ensuing 7 days...
August 15, 2016: Psychopharmacology Bulletin
Bayram Taskin, Ferda E Percin, Mehmet Ali Ergun
Pharmacogenetics is interested in the variable response to drugs depending on the genetic constitution of an individual. Depending on the genetic variation in individuals known as polymorphism; leads to differences in the types of proteins, enzymes or receptors that play a role in the elimination of drugs. Investigation of the correlation between the genotype with phenotype changes in drug metabolism is among the most important topics of today. CYP2D6 gene polymorphisms show clinical efficiency in the use of especially antidepressants, neuroleptics, antiarrhythmic, antihypertensive, beta blocker, and morphine derivatives...
March 1, 2016: Psychopharmacology Bulletin
Andrea E Steuer, Elena Williner, Sandra Staeheli, Thomas Kraemer
Increasing numbers of new psychoactive substances (NPS) among them fentanyl derivatives has been reported by the European monitoring centre for drugs and drug addiction (EMCDDA). Butyrfentanyl is a new fentanyl derivative whose potency ratio was found to be seven compared to morphine and 0.13 compared to fentanyl. Several case reports on butyrfentanyl intoxications have been described. Little is known about its pharmacokinetic properties including its metabolism. However, knowledge of metabolism is essential for analytical detection in clinical and forensic toxicology...
October 13, 2016: Drug Testing and Analysis
Zygmunt Zdrojewicz, Bartłomiej Kuszczak, Natalia Olszak
Ibogaine is a natural chemical compound, which belongs to the indole alkaloid family. It can be naturally found within the root bark of african plant Tabernanthe iboga. Ibogaine plays a significant role among tribal cultures. Ibogaine, in small amount, causes reduction of hunger, thirst and exhaustion. In bigger amount, however, it can cause intensive visions. Other effects include reduction or complete disappearance of absitnence symptoms visible in people addicted to the nicotine, alcohol, methamphetamine, cocaine or opioids, what has been scientifically proven after the tests on animals and small groups of people...
July 29, 2016: Polski Merkuriusz Lekarski: Organ Polskiego Towarzystwa Lekarskiego
Elena Puris, Markku Pasanen, Mikko Gynther, Merja R Häkkinen, Jussi Pihlajamäki, Tapani Keränen, Paavo Honkakoski, Hannu Raunio, Aleksanteri Petsalo
Cocktail phenotyping using specific probe drugs for cytochrome P450 (CYP) enzymes provides information on the real-time activity of multiple CYPs. We investigated different sample preparation techniques and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with simple protein precipitation for the analysis of nine CYP probe drugs and their metabolites in human serum and urine. Specific CYP probe drugs (melatonin, CYP1A2; nicotine, CYP2A6; bupropion, CYP2B6; repaglinide, CYP2C8; losartan, CYP2C9; omeprazole, CYP2C19 and CYP3A4; dextromethorphan, CYP2D6; chlorzoxazone, CYP2E; midazolam, CYP3A4) and their main metabolites, with the exception of 3'-hydroxyrepaglinide, were quantified in human serum and urine using the developed LC-MS/MS method...
October 12, 2016: Analytical and Bioanalytical Chemistry
Hirotaka Amano, Daichi Kazamori, Kenji Itoh
Three major organosulfur compounds of aged garlic extract, S-allyl-L-cysteine (SAC), S-methyl-L-cysteine (SMC), and trans-S-1-propenyl-L-cysteine (S1PC), were examined for their effects on the activities of five major isoforms of human CYP enzymes: CYP1A2, 2C9, 2C19, 2D6, and 3A4. The metabolite formation from probe substrates for the CYP isoforms was examined in human liver microsomes in the presence of organosulfur compounds at 0.01-1 mM by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis...
2016: Biological & Pharmaceutical Bulletin
Rebecca Pleat, Timothy M Cox, T Andrew Burrow, Pilar Giraldo, Ozlem Goker-Alpan, Barry E Rosenbloom, Laura R Croal, Lisa H Underhill, Sebastiaan J M Gaemers, M Judith Peterschmitt
Gaucher disease type 1 is an autosomal recessive disorder caused by deficient activity of the lysosomal enzyme acid β-glucosidase resulting in accumulation of glucosylceramide and clinical manifestations of anemia, thrombocytopenia, hepatosplenomegaly, and skeletal disease. The historic standard of care is intravenous recombinant enzyme therapy with imiglucerase. Eliglustat, an oral substrate reduction therapy, is a first-line treatment for adults with Gaucher disease type 1 who have a compatible CYP2D6-metabolizer phenotype (≈ 95% of patients)...
December 2016: Molecular Genetics and Metabolism Reports
Shiv Bahadur, Pulok K Mukherjee, S K Milan Ahmmed, Amit Kar, Ranjit K Harwansh, Subrata Pandit
OBJECTIVE: Tinospora cordifolia is used for treatment of several diseases in Indian system of medicine. In the present study, the inhibition potential of T. cordifolia extracts and its constituent tinosporaside to cause herb-drug interactions through rat and human liver cytochrome enzymes was evaluated. MATERIALS AND METHODS: Bioactive compound was quantified through reverse phase high-performance liquid chromatography, to standardize the plant extracts and interaction potential of standardized extract...
September 2016: Indian Journal of Pharmacology
Yongjie Zhang, Nico P E Vermeulen, Jan N M Commandeur
AIMS: Oxidative bioactivation of amodiaquine (AQ) by cytochrome P450s to a reactive quinoneimine is considered as an important mechanism underlying its idiosyncratic hepatotoxicity. However, because internal exposure to its major metabolite N-desethylamodiaquine (DEAQ) is up to 240 fold higher than AQ, bioactivation of DEAQ might significant contribute to covalent binding. The aim of the present study was to compare the kinetics of bioactivation of AQ and DEAQ by human liver microsomes and to characterize the CYPs involved in bioactivation of AQ and DEAQ...
October 8, 2016: British Journal of Clinical Pharmacology
Luís F J R Miranda, Karina B Gomes, Pedro A L Tito, Josianne N Silveira, Gerson A Pianetti, Ricardo M D Byrro, Patrícia R H Peles, Fernando H Pereira, Thiago R Santos, Arthur G Assini, Valéria V Ribeiro, Edgar N Moraes, Paulo Caramelli
The clinical response to donepezil in patients with mild and moderate dementia was investigated in relation to the drug plasma concentration and of APOE and CYP2D6 polymorphisms. In a prospective naturalistic observational study, 42 patients with Alzheimer's disease (AD) and AD with cerebrovascular disease who took donepezil (10 mg) for 12 months were evaluated. Their DNA was genotyped, and the donepezil plasma concentrations were measured after 3, 6, and 12 months. Good responders scored ≥-1 on the Mini-Mental State Examination at 12 months in comparison to the baseline score...
October 4, 2016: Journal of Alzheimer's Disease: JAD
Mohd Usman Mohd Siddique, Glen J P McCann, Vinay Sonawane, Neill Horley, Ibidapo Steven Williams, Prashant Joshi, Sandip B Bharate, Venkatesan Jayaprakash, Barij N Sinha, Bhabatosh Chaudhuri
Highly selective CYP1B1 inhibitors have potential in the treatment of hormone-induced breast and prostate cancers. Mimicry of potent and selective CYP1B1 inhibitors, α-naphthoflavone and stilbenes, revealed that two sets of hydrophobic clusters suitably linked via a polar linker could be implanted into a new scaffold 'biphenyl ureas' to create potentially a new class of CYP1B1 inhibitors. A series of sixteen biphenyl ureas were synthesized and screened for CYP1B1 and CYP1A1 inhibition in Sacchrosomes™, yeast-derived recombinant microsomal enzymes...
September 26, 2016: Organic & Biomolecular Chemistry
Jeong-Sun Seo, Arang Rhie, Junsoo Kim, Sangjin Lee, Min-Hwan Sohn, Chang-Uk Kim, Alex Hastie, Han Cao, Ji-Young Yun, Jihye Kim, Junho Kuk, Gun Hwa Park, Juhyeok Kim, Hanna Ryu, Jongbum Kim, Mira Roh, Jeonghun Baek, Michael W Hunkapiller, Jonas Korlach, Jong-Yeon Shin, Changhoon Kim
Advances in genome assembly and phasing provide an opportunity to investigate the diploid architecture of the human genome and reveal the full range of structural variation across population groups. Here we report the de novo assembly and haplotype phasing of the Korean individual AK1 (ref. 1) using single-molecule real-time sequencing, next-generation mapping, microfluidics-based linked reads, and bacterial artificial chromosome (BAC) sequencing approaches. Single-molecule sequencing coupled with next-generation mapping generated a highly contiguous assembly, with a contig N50 size of 17...
October 5, 2016: Nature
Pongkwan Sitasuwan, Cathleen Melendez, Margarita Marinova, Kaylee R Mastrianni, Alicia Darragh, Emily Ryan, L Andrew Lee
Drug monitoring laboratories utilize a hydrolysis process to liberate the opiates from their glucuronide conjugates to facilitate their detection by tandem mass spectrometry (MS). Both acid and enzyme hydrolysis have been reported as viable methods, with the former as a more effective process for recovering codeine-6-glucuronide and morphine-6-glucuronide. Here, we report concerns with acid-catalyzed hydrolysis of opioids, including a significant loss of analytes and conversions of oxycodone to oxymorphone, hydrocodone to hydromorphone and codeine to morphine...
October 2016: Journal of Analytical Toxicology
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