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.