[Main drug interactions at a hospital emergency department. Analysis of 100 cases].

We prospectively reviewed clinical charts of 100 consecutive patients that were admitted during the first trimester 1991 to the Emergency Department of a general hospital in order to determine the more frequent prescribed drugs and their interactions using a computer program (Drug Interaction Program), emphasizing in those drugs used to treat peptic ulcers. Number of drugs prescribed to each patient was 4.20 +/- 1.39. Antacids (39%) and cimetidine (35%) occupied the third and fourth place. There were interactions in 79 patients and in 66 of them (84%) they were important. Antacid and cimetidine were similarly prescribed, but of 35 patients who received cimetidine only 3 (8.5%) had a primary indication for its use (Gastrointestinal bleeding). Significant clinical interactions of cimetidine with other medications are analyzed. Our results indicate that drug interactions are a permanent risk in our hospitals. We suggest to use a computer program on drug interactions or an updated chart of medications in the emergency rooms of our hospitals.