The role of the genetically polymorphic CYP3A5 in the metabolism of CYP3A substrates is unclear. We investigated the contributions of the CYP3A4 and CYP3A5 isoforms to the metabolism of the phosphodiesterase type 5 inhibitors (PDE5Is) sildenafil, udenafil, and vardenafil. In vitro incubation studies of sildenafil N-demethylation, udenafil N-dealkylation, and vardenafil N-deethylation were conducted using recombinant CYP3A enzymes and 15 human liver microsome (HLM) preparations with predetermined CYP3A5 genotypes. Recombinant CYP3A4 and CYP3A5 both produced N-desalkyl metabolites of sildenafil, udenafil, and vardenafil. The catalytic efficiency (Cl(int) = V(max)/apparent K(m)) of the rCYP3A5 isoform for vardenafil N-deethylation was about 3.2-fold that of rCYP3A4, whereas the intrinsic clearance rates for N-dealkylation of both sildenafil and udenafil were similar between rCYP3A5 and rCYP3A4. The metabolite formation activity was higher in HLMs heterozygous for the CYP3A5*3 allele (n = 9) than in HLMs homozygous for CYP3A5*3 (n = 6). These findings suggest that CYP3A5 and CYP3A4 play a significant role in the metabolism of PDE5Is. The genetic polymorphism of CYP3A5 may contribute to interindividual variability in the disposition of PDE5Is, especially vardenafil. Further in vivo studies are needed to confirm the effects of CYP3A5 genotypes on the pharmacokinetics of PDE5Is.
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http://dx.doi.org/10.1124/dmd.107.020099 | DOI Listing |
Cureus
August 2024
Research, Ventolini's Lab, Texas Tech University Health Sciences Center, Odessa, USA.
Se Pu
June 2022
Shanghai Institute of Quality Inspection and Technical Research, State Key Laboratory of Milk and Dairy Products Detection and Monitoring Technology for State Market Regulation, Shanghai 200233, China.
A novel method based on ultra-high performance liquid chromatography-orbitrap high-resolution mass spectrometry (UHPLC-Orbitrap HRMS) was developed for the rapid screening and confirmation of 32 illegally added drugs in slimming and anti-impotence health foods. In addition, the key points of the database establishment and application are summarized. This research focused on the derivatives of illegally added drugs.
View Article and Find Full Text PDFProfiles Drug Subst Excip Relat Methodol
April 2022
Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia; Department of Chemistry, Faculty of Science and Technology, Al-Neelain University, Khartoum, Sudan.
J Chromatogr B Analyt Technol Biomed Life Sci
August 2021
Universidade Federal do Paraná, Department of Pharmacy, 632 Lothário Meissner Avenue, 80210-170 Curitiba, PR, Brazil. Electronic address:
Phosphodiesterase inhibitors (PDE5i) are considered the first line therapy for erectile dysfunction. All PDE5i available on the market are structurally related; their main differences relate to their pharmacokinetic parameters. For these treatments to be effective and safe, it is necessary that these drugs are in the appropriate doses and that they reach adequate concentrations in the plasma.
View Article and Find Full Text PDFUrologiia
May 2021
Tashkent Medical Academy, Tashkent, Uzbekistan.
This article discusses the physiological mechanisms of erection and the pathophysiological basis of erectile dysfunction. Parameters characterizing the features of the pharmacokinetics and pharmacodynamics of drugs from the group of phosphodiesterase type 5 inhibitors (PDE-5i) are presented. The clinical efficacy and possible adverse effects of the most significant PDE-5i are considered.
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