hydrochloride (Ticlid - Syntex), a platelet aggregation inhibitor that has been available in Europe for more than a decade, was recently approved by the U.S. Food and Drug Administration to decrease the risk of thrombotic stroke in men and women who have had premonitory signs of stroke or have had a completed thrombotic stroke. The manufacturer is promoting the drug for patients intolerant to aspirin or with conditions for which aspirin has not been approved (previous thrombotic stroke; transient ischemic attacks in women). The drug has also been used for prevention of myocardial ...

Clopidogrel bisulfate (Plavix - Bristol-Myers Squibb/Sanofi), a new thienopyridine antiplatelet agent similar to ticlopidine (Ticlid - Medical Letter, 34:65, 1992), has been approved by the US Food and Drug Administration (FDA) for secondary prevention of myocardial infarction, stroke and other vascular events.

Aggrenox, a fixed-dose oral combination of aspirin and extended-release dipyridamole, is now being advertised for secondary prevention of a transient ischemic attack (TIA) or ischemic stroke.

Taking aspirin to prevent recurrence or worsening of cardiovascular disease has become a common practice in recent years (Medical Letter, 28:31, 1986). Now, the US Food and Drug Administration is considering whether aspirin can also be advertised for prevention of a first myocardial infarction in previously healthy people.

The FDA has approved prasugrel (Effient - Lilly/Daiichi Sankyo), an oral antiplatelet drug, for use with aspirin to reduce the rate of thrombotic cardiovascular events in patients with acute coronary syndromes (ACS) being managed with percutaneous coronary intervention (PCI). It will compete with clopidogrel (Plavix) for such use.

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

Percutaneous coronary intervention (PCI), such as balloon angioplasty or stent placement, predisposes to subsequent thrombosis. The current pharmacologic approach to prevention of this problem combines an anticoagulant with one or more antiplatelet drugs.