[Evaluation of pharmacokinetic interaction of aphobazole with CYP1A2 drug-substrate in experiments].

The effect of aphobazole on CYP1A2 (drug-marker caffeine) was studied in rats. Aphobazole was administered orally at doses 5 and 25 mg/kg, caffeine 50 mg/kg. The metabolic ratios (MR) for the caffeine metabolites (theobromine and paraxanthine) were accounted. After aphobazole administration at the effective, anxiolytic dose (5 mg/kg) for 4 days (3 times per day every 3 hours) neither the inhibiting nor the inducing effects on NOD1A2 was revealed. Increasing the aphobazole dose up to 25 mg/kg after 2 days repeated administrations of the drug made it possible to reveal a moderate inducing effect. Longer aphobazole administration (4 days), the inducing effect is amplified. Since the MR values on theobromine and paraxanthine after 2-day administration aphobazole exceed similar values in the control of 2.5 and 3.3 times, respectively. MR values after the 4-days aphobazole administration in dose 25 mg/kg exceed similar values in the control of 4.2 times for theobromine and in 6.1 times for paraxanthine.

[In vivo evaluation of the metabolic ratio of CYP2C9 and CYP1A2 drug markers after administration of afobazole in comparison to standard inducers and inhibitors of cytochromes].

The effect of subchronic peroral administration in effective doses of afobazole (5 mg/kg), and cytochrome P450 inductors (rifampicin, 13.4 mg/kg; phenytoin, 10.4 mg/kg) and inhibitors (fluconazole, 35.7 mg/kg; ciprofloxacin, 44.0 mg/kg) on the metabolic ratio (MR) of drugs-markers of CYP2C9 and CYP1A2 activity was studied in rats. Afobazole did not change the MR of compounds metabolized by the P450 isoforms studied. After peroral administration of standard P450 inductors and inhibitors, statistically significant bidirectional effects were identified, which demonstrated the expedience of administering a complex of selected compounds, markers, and CYP2C9 and CYP1A2 activity modificators for comparative evaluation of the effects of new drugs in rats. It is recommended to evaluate the activity of CYP1A2 by determining the MR for one of two caffeine metabolites, paraxanthine or theobromine, and the activity of CYP2C9 by determining the MR of metabolite Exp-3174 to losartan.