TICLOPIDINE AND ANTIPLATELET THERAPY

OBJECTIVE: To review the pharmacology, pharmacokinetics, clinical effi cacy, and toxicity of ticlopidine. Comparisons with other antiplatelet agents are presented, with an emphasis on efficacy, and a recommendat ion is provided regarding ticlopidine's place in therapy. DATA SOURCES : A MEDLINE literature retrieval of English-language journal articles from 1987 to January 1993 and references identified from bibliographie s of review articles and clinical trials. STUDY SELECTION: Randomized, blind, controlled studies of ticlopidine and other antiplatelet agent s were preferentially selected. DATA EXTRACTION: Clinical trials were reviewed in terms of study design, efficacy results, and toxicity. DAT A SYNTHESIS: Ticlopidine is a new antiplatelet agent with a distinct m echanism of action. In the largest trial of the drug for the preventio n of stroke, it was found to be more effective than aspirin in reducin g the risk of stroke or death. Clinical trials have also shown ticlopi dine to decrease the rate of vascular death and myocardial infarction in patients with unstable angina, and to maintain venous graft patency after coronary artery bypass grafting. The use of ticlopidine in diab etic microangiopathy and peripheral vascular disease appears promising , but further studies are needed. Adverse reactions most commonly repo rted with ticlopidine are gastrointestinal complaints; the most severe reaction is transient neutropenia, which is seen in approximately 2.3 percent of patients and is severe in nearly 1 percent. CONCLUSIONS: T iclopidine is a reasonable alternative for use in preventing stroke am ong patients unable to take aspirin or those who do not benefit from a spirin therapy. Its use as first-line therapy is limited by its high c ost and the occurrence of hematologic adverse effects.