Abstract: Aim To study the effect of ketoconazole on the blood concentration and pharmacokinetic action of aminophyllin.Methods The concent raion of aminophyllin was determined by FPIA in rabbits having taken aminophyllin or aminophyllin combined with keto conazole.The two se ries of pharmacokinitics paramete rs were analysed by statistic method.Results The concentration of aminophyllin in the blood could be remarkably descreased by ketoconazole, the V d and AUC in combined group(4.70±1.48 L, 51.94±25.51 mg/L·h^-1)were signif ieant ly different from those in the control group(1.39±0.61 L, 75.74±11.29 mg/ L·h^-1) (P<0.01, P<0.05), the other pharmaco kinetics parameters were not significantly changed. Conclusion The dosage of amino phyllin should be regulated when the two drugs were combined, and the concentration of aminophyllin in blood should be detected.

Key words: aminophyllin, ketoconazole, blood concentration, pharmacokinetics parameters