Abstract: AIM: To investigate the effect of pantoprazole on Cytochrome P4501A2 (CYP1A2),N-acetyltransferase2(NAT2),and xanthine oxidase(XO) activity in human and to forecast the drug-drug interaction with it,so as to instruct clinician to prescribe rationally.METHODS: In thirty volunteers,use two-way cross design,caffeine was used as a metabolic probe for CYP1A2 、NAT2,and XO,before and after pantoprazole administration,urine samples were collected.The contents of five major metabolites of caffeine in the urine were determined by RP-HPLC method and then evaluated the activity change of CYP1A2 、NAT2,and XO by the ratio of metabolites of caffeine.RESULTS: It was found that the average activity of CYP1A2 、NAT2,and XO were 3.37±1.22,0.50±0.09,0.49±0.09 with before treatment,and 7 days after treatment,the average activity of CYP1A2 、NAT2,and XO were 3.50±1.23,0.48±0.12,0.48±0.13.There were no statistical significance between before treatment and after treatmen(P>0.05).CONCLUSIONS: Pantoprazole have no influence on CYP1A2 、NAT2,and XO,so pantoprazole do not modify the efficacy of drugs which metabolized by CYP1A2 、NAT2,and XO taken simultaneously.

Key words: pantoprazole, caffeine metabolites, RPHPLC, cytochrome P4501A2 N-acetyltransferase2, xanthine oxidase