The effect of diltiazem on coronary thrombosis in the conscious canine.

The effect of diltiazem vs. saline was studied in a conscious canine model of coronary thrombosis. Diltiazem given as a 0.75 mg/kg loading dose intravenously followed by 0.4 mg/kg intravenously every 4 h for 24 h had no significant effect on thrombus wet weight, left ventricular infarct size, frequency of ventricular arrhythmias or ex vivo platelet aggregation. The search for antithrombotic agents using in vitro or ex vivo platelet aggregation studies should include concomitant in vivo thrombosis studies using therapeutic dosages of the drug in question.