Abstract: AIM: To determine the effects of MDR1C3435T on the pharmacokinetics of telmisartan in healthy Chinese volunteers and blood concentration in hypertension patients.METHODS: The genotype on MDR1C3435T in 19 healthy Chinese volunteers who were received a single oral dose of 40 ng telmisartan and 61 hypertension patients who were received oral of 40 mg telmisartan every day after a month was detected by PCR RFLP method, the relationship of MDR1C3435T polymorphism and steady-state blood concentrations of telmisartan were determinated by HPLC-MS. The pharmacokinetics of telmisartan in health volunteers and steady-state telmisartan concentrations of patients with hypertension were compared among MDR1C3435T genotypes.RESULTS: Among the 61 cases of hypertension patients, the frequencies of C3435T CC, C3435T TT and C3435T CT were 39.34%, 11.48% and 49.18%, respectively. There were no differences between normal people and hypertension patients in MDR1 ditribution. No significant difference in C_max, t_max, t_1/2, AUC_0-48, AUC_0-∞ and CL among MDR1 C3435T genotypes in health volunteers and no significant difference in steady-state concentration among MDR1C3435T genotypes in hypertension patients were observed. CONCLUSION: The MDR1 C3435T polymorphism does not affect the blood concentration and pharmacokinetics of telmisartan.

Key words: Telmisartan, Pharmacokinetics, Steady-state concentration