The Journal of the American Medical Association published the results of systematic review earlier this year that aimed to clarify the most appropriate daily aspirin dose for the prevention of cardiovascular disease. This study has also been the topic of an InfoPOEM and has been covered in a podcast!
In America the most commonly used doses are 81mg per day and 325mg per day. In Britain doses of 75mg per day, 150mg per day and 300mg per day are used.
This review used MEDLINE and EMBASE to identify English-language research published before February 2007 that contained either aspirin or acetylsalicylic acid and dose in the paper. The bulk of the evidence identified consisted of observational studies of secondary prevention.
Daily doses of aspirin greater than 75 to 81 mg/d were not found to enhance efficacy, but larger dosages were associated with an increased risk of bleeding events, mainly gastrointestinal in nature.
The authors conclude that, "clinical data do not support the routine, long-term use of aspirin dosages greater than 75 to 81 mg/d in the setting of cardiovascular disease prevention".
Action: Clinicians should ensure that aspirin usage for the prevention of cardiovascular disease does not routinely exceed a daily dose of 75mg.
Thanks to Andrew White, Bolton PCT for spotting this study.