The in vitro effect of amrinone on platelet aggregation in human whole blood.

Amrinone was found to inhibit platelet aggregation in human whole blood in a dose dependent manner, and at physiological levels of the drug. Statistically significant drug-related decreases in aggregation were observed with collagen, ADP and arachidonic acid. Inhibition of aggregation was most marked with arachidonic acid, where greater than 90% inhibition was achieved at a drug concentration of 25 mugml-1. The aggregation profiles presented indicate that amrinone inhibits aggregation primarily through inhibition of thromboxane A2 synthesis.