Abstract
A total of 167 264 symptoms were recorded in numerical shorthand during a ten years period in a general practice. Computer analysis yielded 1535 adverse reactions with the drug prescribed. Especially prominent were reactions from three antibiotics (13% of all reported reactions), most of which were alimentary symptoms. Ampicillin also induced rashes reported at a rate of 5.2 per thousand prescriptions. Reactions to an oral contraceptive (Minovlar) were the most frequent to a single named drug, being 25.9% of prescriptions for that drug. A worldwide total of around one trillion symptoms seems likely before AD 2000. Computers could be used to detect the unpredictable side effects, as with practolol. Various 'costs' involved are noted, together with wider questions.