[Pharmacokinetic and electocardiographic study of oral verapamil sustained-release tablet in 10 Chinese volunteers].
Both verapamil pharmacokinetics and electrocardio graphic changes in 10 Chinese volunteers were studied after po 240 mg of verapamil sustained release tablet. A one-compartment model with zero-order absorption gave a better fitting to concentration--time data with values of r2 > 0.96. The main pharmacokinetic parameters obtained were: Tmax, 5.9 +/- 1.6 h; Cmax, 118.9 +/- 37.2 micrograms.L-1; T1, 5.4 +/- 1.5 h; k0, 30.5 +/- 17.5 micrograms.L-1.h-1; T1/2, 10.8 +/- 4.9 h; MRT, 15.4 +/- 3.2 h and AUC. 1.96 +/- 0.82 mg.h.L-1. There were significant prolongations of PR intervals after dose. Relationships between PR interval changes and plasma concentrations of verapamil were better fitted to sigmoidal model, with r2 > 0.98. The corresponding pharmacodynamic parameters were estimated. EC50, 64.6 +/- 16.9 micrograms.L-1, Emax, 54 +/- 11 ms and s, 1.68 +/- 0.66.
Liu
X D
XD
Cente of Pharmacokinetics and Metabolism, China Pharmaceutical University, Nanjing.
Xie
L
L
Wang
J
J
Zhou
Y S
YS
Wang
Z
Z
Liu
G Q
GQ
D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D003692:Delayed-Action Preparations; D004562:Electrocardiography / Q000187:drug effects*; D006801:Humans; D008297:Male; D014700:Verapamil / Q000008:administration & dosage / Q000493:pharmacokinetics*
D000889:Anti-Arrhythmia Agents; D003692:Delayed-Action Preparations; D014700:Verapamil