THE EFFECT OF CIMETIDINE AND RANITIDINE ON COGNITIVE FUNCTION IN POSTOPERATIVE CARDIAC SURGICAL PATIENTS

Objective: To compare the incidence of delirium in postoperative cardi ac surgical patients treated with either cimetidine or ranitidine. Met hod: Cardiac surgery patients were randomized to receive either cimeti dine or ranitidine postoperatively. Each patient underwent three Mini- Mental Status Examinations (MMSE) and the medical record was reviewed for pertinent past medical history, laboratory data, and evidence of d elirium on three occasions: one day preoperatively (before H-2 blocker was given), in the early postoperative period (while receiving the H- 2 blocker); usually two days postoperatively on the day of hospital di scharge (several days after the H-2 blocker had been discontinued). Re sults: Overall, both groups in the early postoperative period showed a significant decrease in the MMSE score (27.11 +/- 4.44 to 25.38 +/- 2 .87, mean +/- SD; t = 5.16, p < .0005), which resolved by the time of hospital discharge. There was no significant difference between cimeti dine and ranitidine. Both age and preoperative MMSE score were strongl y associated with the development of delirium. Conclusions: We found n o significant difference between cimetidine's versus ranitidine's effe ct upon cognitive functioning in the postoperative cardiac surgical pa tient. This was true even when controlling for age and length of stay.