The interaction of ibuprofen and diclofenac with aspirin in healthy volunteers

Abstract

Background and purpose: Aspirin reduces the risk of myocardial infarction and stroke by inhibiting thromboxane production in platelets. This inhibition can be competitively antagonized by some non-steroidal anti-inflammatory drugs (NSAIDs). Experimental approach: By measuring thromboxane B2 production in healthy volunteers, we investigated whether ibuprofen (800 mg three times daily for 7 days) or diclofenac (50 mg three times daily for 7 days) taken concurrently with aspirin 80 mg (once daily for 7 days) influenced the inhibitory effect of aspirin. The effects were compared with aspirin 30 mg (once daily for 7 days), which is the lowest dose of aspirin with a proven thromboprophylactic effect. Key results: The median percentage inhibition of thromboxane B2 levels by 30 mg or 80 mg aspirin was 90.3% (range 83.1-96.0%) and 98.0% (range 96.8-99.2%) respectively. The inhibition by concurrent administration of slow release diclofenac and 80 mg aspirin was 98.1% (range 97.2-98.9%), indicating no interference between aspirin and diclofenac. The inhibition decreased significantly by concurrent administration of immediate release ibuprofen and 80 mg aspirin (86.6%; range 77.6-95.1%) to a level less than 30 mg aspirin. Conclusions and implications:As alternatives are easily available, NSAIDs such as diclofenac should be preferred to ibuprofen for combined use with aspirin.

Topical diclofenac does not affect the antiplatelet properties of aspirin as compared to the intermediate effects of oral diclofenac: A prospective, randomized, complete crossover study

“…In contrast to the unanimous conclusions of the in vitro studies, in vivo studies depict a more complicated picture. Schujit et al looked at the interaction between oral diclofenac and aspirin by measuring serum thromboxane B 2 levels in healthy volunteers . These volunteers received aspirin 80 mg once daily with oral diclofenac 50 mg 3 times a day for 7 days.…”

Influence of nonsteroidal anti-inflammatory drugs on aspirin’s antiplatelet effects and suggestion of the most suitable time for administration of both agents without resulting in interaction

“…The antiplatelet effects of aspirin may be decreased due to co-administration of ibuprofen [3, 10, 11], and a warning is included in the package inserts of both aspirin and ibuprofen. When ibuprofen binds with COX-1, it hinders acetylation of the serine residue by aspirin [3].…”

Drug–Drug Interactions in Cardiovascular Catheterizations and Interventions

“…Catella-Lawson et al (22) demonstrated that the antiplatelet effect of aspirin is attenuated if ibuprofen is administered up to 12 h after enteric-coated aspirin administration. Data are less clear with other NSAIDs but are suggestive in total that nonselective NSAIDs (e.g., indomethacin, naproxen) also interfere with the antiplatelet effects of aspirin in a similar manner as ibuprofen, whereas use of more COX-2 selective agents (e.g., celecoxib, diclofenac, meloxicam) likely do not interfere with aspirin (27)(28)(29). Thienopyridine P2Y 12 inhibitors.…”