FDA offers recipe for proper mixing of aspirin and ibuprofen

Aspirin is widely used to decrease the risk of heart attacks. It is an essential part of secondary prophylaxis and typically is recommended to persons who have not had a cardiac event but who have an increased risk of developing coronary artery disease. The American Heart Association recommends prophylactic aspirin for those who have a ten year heart attack risk of 10% or greater and the usually-much-more conservative U.S Preventive Services Task Force recommends aspirin for those who have a five year risk of 3 % or higher.

Ibuprofen is widely used for a variety of aches and pains and its use is prevalent in the same age group who usually qualify for aspirin prophylaxis. However, there is evidence that ibuprofen may interfere with the beneficial effect that aspirin has on blood platelets. It is thought that ibuprofen and perhaps other NSAIDs interfere with aspirin gaining access to the molecular site on which it acts to inhibit platelet aggregation which is the putative mechanism involving in aspirin's success in decreasing coronary events.( Ibuprofen and aspirin are thought to chemically link up to sites in close proximity so that ibuprofen's presence may "crowd out" aspirin)

The FDA has recently published a paper explaining what is known about the asa-ibuprofen interaction issue and what practically can be done to enjoy whatever cardioprotective effect aspirin has and still be able to take ibuprofen for various pains. It is well worth reading and perhaps having copies handy to give patients.

Basically the advice is this:

Wait at least 1/2 hour after taking immediate release aspirin before taking ibuprofen. Wait 8 hours after taking 400 mg. of ibuprofen before taking aspirin.

The above advice does not apply to the popular enteric coated aspirin (ECASA) whose absorption is slower and 1/2 hour may not be long enough for aspirin to complete its inhibition of cyclooxygenase.The FDA did not believe there was adequate evidence to make specific recommendations regarding other NSAIDs-other than a general cautionary note. However, one recent article provided some data indicating a similar problem with the combination of aspirin and naproxen.