TUESDAY, March 17 (HealthDay News) -- The optimum daily dose of aspirin for prevention of cardiovascular events is probably between 75 and 81 mg, as a 100-mg dose or more has no obvious benefit and may cause harm in patients who are also taking clopidogrel, according to a report published in the March 17 issue of the Annals of Internal Medicine.
Steven R. Steinhubl, M.D., of The Medicines Company in Zurich-Flughafen, Switzerland, and colleagues analyzed data from a double-blind, placebo-controlled, randomized trial of 15,595 patients with cardiovascular disease or multiple risk factors, who were randomized to receive 75 mg a day of clopidogrel or placebo. While 7,180 patients also received 75 or 81 mg a day of aspirin, 4,961 received 100 mg, and 3,454 received either 150 mg or 162 mg.
The odds of myocardial infarction, stroke or cardiovascular death were similar regardless of the dose, as they were for the incidence of life-threatening or severe bleeding, the investigators found. However, for patients also taking clopidogrel, there was a non-statistically significant association with reduced efficacy and increased harm in patients taking aspirin doses of more than 100 mg a day, the researchers report.
"These results suggest that daily aspirin doses of no greater than 81 mg optimize efficacy as well as safety in patients receiving aspirin for long-term primary and secondary prevention," the authors write.
The trial from which the data used in the study was extracted was funded by Sanofi-Aventis and Bristol-Myers Squibb. Study authors disclosed ties to those and other pharmaceutical companies.