Evaluation of the relationship between polymorphisms in CYP2C19 and the single-dose pharmacokinetics of omeprazole in healthy Chinese volunteers: A multicenter study

Drug interaction evaluation of the novel phosphodiesterase type 5 inhibitor tunodafil (youkenafil): Effects of tunodafil on omeprazole pharmacokinetics based on CYP2C19 gene polymorphism, and effects of ritonavir on tunodafil pharmacokinetics

PURPOSE

To evaluate the drug-drug interactions (DDI) of tunodafil (youkenafil), a novel phosphodiesterase type 5 inhibitor, its inhibitory effects on CYP450 enzymes in vitro and its clinical trials in combination with ritonavir or omeprazole were conducted.

METHODS

The inhibitory effect of tunodafil on seven major CYP450 enzymes in human liver microsomes was investigated by probe substrate method. The effect of tunodafil on the pharmacokinetics of omeprazole (CYP2C19 substrate) in 40 healthy subjects, who received a single dose of 40 mg omeprazole in combination with tunodafil on the day 8 after taking 100 mg tunodafil daily for 7 days, was assessed based on CYP2C19 genotypes. The clinical DDI of ritonavir (potent CYP3A4 inhibitor) on tunodafil was studied in 28 healthy subjects who received a single dose of 50 mg tunodafil in combination with ritonavir on the day 6 after taking ritonavir twice a day for 5 days.

RESULTS

Tunodafil showed moderate inhibition on CYP2C19 and CYP3A4/5 in vitro. When co-administration omeprazole with tunodafil, the AUC of omeprazole in the Extensive, Intermediate and Poor Metabolizers increased by 26 %, 37 % and 21 %, respectively. After co-administration tunodafil with ritonavir, ritonavir increased the AUC and Cmax of tunodafil in human by about 78- fold and 13-fold respectively.

CONCLUSIONS

Tunodafil slightly increased omeprazole exposure in the Extensive and Intermediate Metabolizers of CYP2C19, but had no significant effect on omeprazole exposure in the Poor Metabolizers. Ritonavir could strongly inhibit the metabolism of tunodafil, and the combination of tunodafil with ritonavir should be prohibited.

Notable drug-drug interaction between omeprazole and voriconazole in CYP2C19 *1 and *2 (rs4244285, 681G>A) alleles in vitro

The drug-drug interaction (DDI) and CYP2C19 genetic variation can lead to a high blood concentration of voriconazole. CYP2C19 is a highly genetically polymorphic enzyme, and CYP2C19*2 is more frequent among Asians associated with reduced metabolism of drugs. Clinical study found that co-administration with omeprazole significantly increased voriconazole concentrations and there was an additive effect in CYP2C19*2 allele.CYP2C19 rs4244285 (681G>A) is the key polymorphism of CYP2C19*2 allele. This study aims to describe the in vitro effects of omeprazole on CYP2C19*1 and *2 (681G>A), and determine how CYP2C19 polymorphisms influence the DDI between omeprazole and voriconazole.Using the lentiviral expression system, we successfully generated HepG2-derived cell lines stably expressing CYP2C19*1 and *2 (681G>A). The results showed that the CYP2C19 mRNA level, protein level, and enzymatic activity were lower in HepG2-CYP2C19*2 (681G>A) than HepG2-CYP2C19*1 cells. Our study also showed that the inhibition rates of omeprazole on voriconazole had no significantly differences between CYP2C19*1 and *2 (681G>A). But the IC50 of omeprazole on CYP2C19*1 slightly lower than CYP2C19*2 (681G>A).Moreover, omeprazole inhibited CYP2C19 protein level in cells carrying CYP2C19*1 and CYP2C19*2 (681G>A). Our study demonstrated that omeprazole could inhibit voriconazole metabolism in both CYP2C19*1 and CYP2C19*2 (681G>A).

Relationships of Proton Pump Inhibitor-Induced Renal Injury with CYP2C19 Polymorphism: A Retrospective Cohort Study

Proton pump inhibitors (PPIs) have recently been reported to be linked with nephrotoxicity. PPIs are metabolized mainly or partly by cytochrome P450 2C19 (CYP2C19). However, the relationship between CYP2C19 genetic polymorphism and PPI-induced nephrotoxicity is unclear. In this study, we aimed to analyze the association between the time of occurrence of renal injury by PPIs, including lansoprazole, esomeprazole, rabeprazole, and vonoprazan, and CYP2C19 metabolizer status classified by CYP2C19 genotypes. Patients prescribed PPIs were reviewed in this retrospective cohort study. The primary outcome was the time to a 30% decrease in estimated glomerular filtration rate (eGFR) from baseline. In patients treated with lansoprazole, the time to a 30% decrease in eGFR for the CYP2C19 poor metabolizer (PM) group was significantly shorter than that for the non-PM group (hazard ratio for PM vs. non-PM, 2.43, 95% confidence interval, 1.21 to 4.87, P = 0.012). In contrast, in patients that received esomeprazole, rabeprazole, or vonoprazan, no significant differences were found in the time to a 30% decrease in eGFR between non-PM and PM groups. The adjusted hazard ratios for the time to a 30% eGFR decrease in patients treated with lansoprazole were significantly higher for CYP2C19 PM, hypertension, and a history of myocardial infarction. In conclusion, this retrospective study showed that CYP2C19 metabolizer status was associated with the time to a 30% eGFR decrease in patients treated with lansoprazole, but not with esomeprazole, rabeprazole, or vonoprazan.

Pharmacokinetics and bioequivalence evaluation of omeprazole and sodium bicarbonate dry suspensions in healthy Chinese volunteers

Omeprazole and sodium bicarbonate dry suspension are effective treatments for acid-related disorders. This study compared the bioequivalence and safety of the two formulations of omeprazole and sodium bicarbonate powder and assessed how CYP2C19 gene polymorphisms affect pharmacokinetics (PK). A single-center, randomized, single-dose, 2-sequence and 2-period crossover method was performed in forty healthy Chinese subjects. Blood samples were collected after a single dose for PK (AUC0-∞, AUC0-t, and Cmax) analysis. The concentrations of Omeprazole in human plasma were determined by HPLC-MS/MS. Besides, the gene polymorphisms of CYP2C19 were assessed by Sanger sequencing. The geometric mean ratios (90% confidence interval) [GMR (95% CI)] of Test/Reference preparation for Cmax: 95.2% (88.48%, 102.43%), AUC0-t: 97.47% (94.4%, 101.02%), AUC0-∞: 97.68% (94.27%, 101.21%) were within the range of 80.00-125.00%. The non-parametric test showed no statistical difference in Tmax between the two groups (p > 0.05). All drugs were well tolerated, no severe adverse reactions occurred, and no significant differences in adverse events between the two drugs. For CYP2C19 gene polymorphisms, the results showed that of 40 subjects, 12 subjects were extensive metabolizers, 24 were intermediate metabolizers, and 4 were poor metabolizers, the frequency of metabolic genotypes were 30%, 60%, and 10%. And the allele distributions for CYP2C19 were *1, *2, and *3 at 60%, 38.75%, and 1.25%. Both the CYP2C19 alleles and metabolic genotypes were consistent with other studies in Chinese. The results of PK parameters showed that different genotypes of CYP2C19 lead to significant differences in t1/2, AUC0-t, AUC0-∞ and Cmax, but no significant differences in Tmax in each group. At the same time, we confirmed that the PK parameters of the test and reference had no differences between the males and females. This study has shown that the pharmacokinetic parameters of the two formulations are not significantly different, which showed bioequivalence and exemplary safety. CYP2C19 gene polymorphism significantly differed in the PK parameters of omeprazole sodium bicarbonate powder.