Rapid platelet inhibition after a single capsule of Aggrenox®: Challenging a conventional full‐dose aspirin antiplatelet advantage?

• Published in: American journal of hematology Vol. 72; no. 4; pp. 280 - 281
• Main Authors: Serebruany, Victor L., Malinin, Alex I., Sane, David C.
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01.04.2003; Wiley-Liss
• Subjects: Adenosine Diphosphate - pharmacology; Adult; Aggrenox; Antianginal agents. Coronary vasodilator agents; aspirin; Aspirin - administration & dosage; Aspirin - pharmacology; Aspirin, Dipyridamole Drug Combination; Biological and medical sciences; Blood Platelets - drug effects; Blood. Blood coagulation. Reticuloendothelial system; Capsules; Cardiovascular system; dipyridamole; Dipyridamole - administration & dosage; Dipyridamole - pharmacology; Dose-Response Relationship, Drug; Drug Combinations; Epinephrine - pharmacology; Female; Humans; Male; Medical sciences; Middle Aged; Pharmacology. Drug treatments; platelet aggregation; Platelet Aggregation - drug effects; Platelet Aggregation Inhibitors - administration & dosage; Platelet Aggregation Inhibitors - pharmacology; Platelet Function Tests; Risk Factors; Stroke - epidemiology; Stroke - prevention & control; Time Factors; Antianginal agent; Human; Prostaglandin-endoperoxide synthase; Drug combination; Enzyme; Coronary vasodilator agent; Treatment efficiency; Dipyridamole; Enzyme inhibitor; Acetylsalicylic acid; Biological activity; Antiplatelet agent; Non steroidal antiinflammatory agent; Chemotherapy; Analgesic; Cohort study; Antipyretic; Oxidoreductases; Salicylates
• ISSN: 0361-8609; 1096-8652
• DOI: 10.1002/ajh.10290

Aggrenox® is a novel combination of 25 mg of aspirin with 200 mg of sustained release dipyridamole. In a recent large trial (ESPS‐2), Aggrenox® was twice as effective for secondary stroke prevention as either aspirin or dipyridamole alone, suggesting superior platelet inhibition for combination therapy. We sought to compare the time course of platelet inhibition with Aggrenox® compared with escalating doses of non‐enteric coated aspirin. Data from 10 healthy volunteers were analyzed. Fasting subjects sequentially ingested aspirin in the following order: 325 mg, 81 mg, 25 mg, and then one pill of Aggrenox® after a 3‐week interval for aspirin washout. Platelet function was assessed at baseline, 15, 30, 60, and 120 min post‐medication with 5 μM epinephrine and 5 μM ADP using conventional aggregometry. Aspirin provided significant (P < 0.01) reduction of platelet aggregation at 15 min post 325 mg, 30 min post 81 mg, and unexpectedly within 60 min after taking 25 mg of aspirin. A single pill of Aggrenox® also inhibited platelet aggregation within 1 hr after administration. Aspirin inhibits platelets remarkably fast. Both Aggrenox® and a matching dose of aspirin (25 mg) exhibit significant antiplatelet properties within 60 min after ingestion. These findings could be relevant for the optimal balance between the reduction of vascular events via sufficient and rapid platelet inhibition and low risk of bleeding complications associated with the Aggrenox® therapy. Am. J. Hematol. 72:280–281, 2003. © 2003 Wiley‐Liss, Inc.