Original Articles: PDF OnlyPHARMACOKINETICS AND PHARMACODYNAMICS OF A NEW CALCIUM CHANNEL BLOCKER MPC-1304 IN HYPERTENSIVE SUBJECTSKumagai, Yuji; Fujimura, Akio; Shiga, Tsuyoshi; Sunaga, Ken-ichiro; Ohashi, Kyo-ichi; Ebihara, Akio Author Information Department of Clinical Pharmacology, Jichi Medical School, Tochigi, Japan. American Journal of Therapeutics: December 1996 - Volume 3 - Issue 12 - p 807-810 Buy Abstract The pharmacokinetic and pharmacodynamic properties of a new calcium channel blocker MPC-1304 (MPC) were examined following a single 10 mg oral dose of MPC in six hypertensive subjects. Blood samples for measurement of MPC and its active metabolite (MPC-Keto-H2) were obtained, and blood pressure was measured just before and at 1, 2, 4, 6, 8, 12 and 24 h after administration. Plasma concentrations of MPC-Keto-H2 were significantly higher than those of MPC at every observation point. The value of maximum plasma concentration of MPC-Keto-H2 was 10 times greater than that of MPC. The antihypertensive effect of MPC was observed at 4 h after administration and persisted up to 8 h. A plot of plasma concentrations of MPC versus reductions in blood pressure showed an anticlockwise hysteresis loop. These results suggest that the active metabolite MPC-Keto-H2 contributes in part to the antihypertensive action of MPC, the delayed distribution of MPC into the effector site, or both. © Williams & Wilkins 1996. All Rights Reserved.