seventy-seven horses with atrial fibrillation ( af ) were treated orally with quinidine sulfate ( qs ) at the university of pennsylvania , school of veterinary medicine , thirty-seven horses ( 48 % ) had adverse reactions to qs , the most common of which were nasal mucosal edema , anorexia , colic , and diarrhea .
C0004238
atrial fibrillation
C0034415
quinidine sulfate