Effects of Selective and Nonselective Nonsteroidal Anti-inflammatory Drugs on Antibiotic Efficacy of Experimental Group A Streptococcal Myonecrosis

Background. Epidemiologic evidence suggests that nonsteroidal anti-inflammatory drugs (NSAIDs) contribute to more severe group A streptococcal (GAS) infections, yet a beneficial role for NSAIDs has been demonstrated in other experimental bacterial infections. Methods. Nonselective (ketorolac tromethamine, ibuprofen, indomethacin), COX-1-selective (SC-560), or COX-2-selective (SC-236) NSAIDs +/- antibiotics (penicillin, clindamycin) were given to mice challenged intramuscularly with M-type 3 GAS and disease course was followed for 14 days. Results. All nonselective NSAIDs significantly accelerated mortality and reduced antibiotic efficacy; COX-selective NSAIDs had no significant effects. Conclusions. Use of nonselective NSAIDs, either alone or as adjuncts to antibiotic therapy, for GAS soft tissue infection may contribute to worse outcomes.