Cimetidine prophylaxis after renal transplantation.

Over an 18 month period 66 consecutive kidney transplant patients at risk of gastrointestinal bleeding were treated prophylactically with the histamine H2-blocker cimetidine, without antacids. The incidence of gastrointestinal bleeding, the number of rejection episodes, and graft survival were compared with those of 66 patients, who had received a transplant in the period immediately preceding the start of the study, and who had never received cimetidine. The incidence of gastrointestinal hemorrhage was significantly reduced in the cimetidine-treated patients (P less than 0.05). In addition, cimetidine treatment neither increased the total number of rejection episodes nor did it impair long-term graft survival.