Ticlopidine and antiplatelet therapy.

OBJECTIVE: To review the pharmacology, pharmacokinetics, clinical efficacy, and toxicity of ticlopidine. Comparisons with other antiplatelet agents are presented, with an emphasis on efficacy, and a recommendation 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 bibliographies of review articles and clinical trials. STUDY SELECTION: Randomized, blind, controlled studies of ticlopidine and other antiplatelet agents were preferentially selected. DATA EXTRACTION: Clinical trials were reviewed in terms of study design, efficacy results, and toxicity. DATA SYNTHESIS: Ticlopidine is a new antiplatelet agent with a distinct mechanism of action. In the largest trial of the drug for the prevention of stroke, it was found to be more effective than aspirin in reducing the risk of stroke or death. Clinical trials have also shown ticlopidine 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 diabetic microangiopathy and peripheral vascular disease appears promising, but further studies are needed. Adverse reactions most commonly reported 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: Ticlopidine is a reasonable alternative for use in preventing stroke among patients unable to take aspirin or those who do not benefit from aspirin therapy. Its use as first-line therapy is limited by its high cost and the occurrence of hematologic adverse effects.