Warfarin-Rifampin Drug Interaction in a Pediatric Patient.

Rifampin has been documented to significantly attenuate the effect of warfarin in adult patients. No data have been presented on the use of rifampin and warfarin in a pediatric patient. We report an extreme case of increased warfarin metabolism in a pediatric patient who was concomitantly receiving rifampin, despite receiving other medications that significantly decrease warfarin metabolism. The inhibitory effect of rifampin on warfarin therapy may be amplified in pediatric patients.