抄録
Effects of various co-administrated drugs and dosing conditions on the bioavailability of diltiazem were studied in dog and human in single oral doses. Bioavailability was assessed from plasma diltiazem levels in dog and urinary diltiazem excretion in human. In dog, absorption of diltiazem delayed on the co-administration of food and antacid, depending on dissolution rate of diltiazem from dosage form. Other bioavailability parameters were not changed by these dosing conditions. Administration of alcohol and dipyridamole, on the other hand, markedly increased the peak level and area under the curve of diltiazem. Biological half-lives were not altered as compared with diltiazem alone on any occasion. In healthy subjects, sleep caused a delay in diltiazem absorption. Results in experiments of dog and human did not parallel except time to reach the peak level. The relationship between number of co-administrated drugs in a clinic and the steady state plasma diltiazem levels was not significant. It is considered that the bioavailability of diltiazem preparation was rather unsusceptible to the dosing conditions.
