Abstract
The clinical significance of drug interactions was studied in a 1052-bed university teaching hospital using a retrospective method. Seven DIAL (Drug Interaction Alert List) drugs, including digitalis, gentamicin, tetracyclines, phenylbutazone, guanethidine, and anabolic steroids, were selected for study. The medication orders of all patients were screened for one month to determine the incidence of potentially interacting drug combinations. The charts of patients towhom these combinations were prescribed were searched for signs of drug interactions.
The incidence of potentially interacting drug combinations with digitalis andgentamicin was high, but with others very low. Twenty-five out of 58 patientsstudied had some sorts of adverse drug reactions which could be possibly due todrug interacions. However, after analysing each patients, we came to the conclusion that 5 were probable, six possible, and 14 non-drug interactions. Theprobable adverse drug interactions occurred as ; 5%, digitalis-potassium-losingdiuretics ; 5.6%, gentamicin-cephalosporines; 67%, warfarin-phenytoin ; and 33%, warfarin-phenobarbital combinations. But most of these interactions seem ofminor significance clinically.
