Postmarketing surveillance of the safety of cimetidine: 12 month mortality report.

A total of 9928 patients taking cimetidine and 9351 controls were recruited to a postmarketing drug surveillance study in Glasgow, Nottingham, Oxford, and Portsmouth. Takers were identified by the Prescription Pricing Bureau at Nottingham and by dispensing pharmacists at the other three centres. All but 1.2% of the takers and 1.6% of the controls were successfully followed up for one year during which hospital visits and deaths were recorded. Three hundred and seventy five of the cimetidine takers and 198 of the controls are known to have died. Most of the difference in mortality was accounted for by an excess among the takers of deaths from cancers of the oesophagus, stomach, colon, and lung; from neoplasms of the lymphatic and haematopoietic system; and from ischaemic heart disease, chronic liver disease, and accidents and poisonings. So far as can be assessed, however, none of these drug-disease associations represented adverse effects of cimetidine treatment; on the contrary, they resulted from cimetidine being used, knowingly or unknowingly, for treating the symptoms of various diseases or for alleviating adverse effects of other agents such as corticosteroids, non-steroidal anti-inflammatory drugs, and radiotherapy. No evidence of any fatal adverse effects of cimetidine emerged in this study.