Effect of calcium channel blocker (diltiazem) on platelet aggregation.

Platelet aggregation with collagen, ADP and sodium arachidonate was significantly inhibited by 0.48 and 0.24 mg/ml of diltiazem but no significant effect occurred with 0.024 mg/ml of diltiazem. It is suggested that the antiplatelet property of diltiazem may be utilized in clinical setting and diltiazem may be tried synergistically with other antiplatelet drugs.