The Dose for Prophylaxis

There is little evidence that the degree of prevention is related to the dose of aspirin. Overviews give no evidence of any significant differences between the long-term protection given by doses between about 150 mg and 1 g per day, though there is perhaps a suggestion that protection from 75-150 mg per day may be slightly greater than that from doses greater than 500 mg per day. (34)

There is therefore no reason to dissent from the WHO recommendation of 100-300 mg daily, except possibly in ‘early’ or ‘immediate’ aspirin, in which case it may be advisable to give at least 300 mg. The formulation of the aspirin appears to matter little as all preparations are well absorbed, with the possible exception of enteric-coated tablets. (53)