Predisposing factors in adverse reactions to drugs.

Predisposing factors were sought in 118 patients who developed adverse drug reactions in hospital. Significantly more patients of 60 years and over, and more women than men, developed adverse drug reactions. Patients with reactions had more drugs before the development of the reaction than patients who did not develop reactions. A previous adverse drug reaction and a history of allergic disease were significant factors, while a history of jaundice or the presence of diabetes mellitus and renal disease was not.