Cimetidine toxicity: an assessment of 881 cases.

We reviewed 881 documented cimetidine overdoses. The data were compiled and analyzed retrospectively from 2,612,236 poisoning cases reported to two nationwide poison surveillance systems from 1978 through 1985. Only cases of cimetidine exposures without coingestants were included. Age, sex, symptom occurrence, treatment site, reason and route of exposure, and medical outcome data were evaluated. Eight hundred eighty-one cases met the criteria and were analyzed. Children between 12 and 35 months of age accounted for 43% of the cases and 97% of all exposures were acute. Intentional overdosage accounted for 21%; 76% were accidental in nature. Gastric emptying was performed in 34%. No symptoms were observed in 79% of the cases, which included ingestions of up to 15 g of cimetidine. Only three patients had moderate clinical manifestations. No patients had major medical complications and there were no fatalities. Even patients in the moderate category experienced no life-threatening toxic manifestations. Cimetidine appears to have an extremely high therapeutic index in both children and adults and demonstrates a remarkable safety profile following acute overdose.