Ranitidine improves postoperative monocyte and neutrophil function

The histamine H2-receptor antagonist ranitidine hydrochloride has been shown to improve trauma-, blood transfusion-, and sepsis-induced immunosuppression.

To evaluate the effect of ranitidine on postoperative impairment in monocyte and neutrophil function.

Twenty-four patients undergoing major elective abdominal surgery were randomized to receive adjuvant treatment with ranitidine hydrochloride (100 mg) administered twice a day intravenously from skin incision for 4 days, followed by oral ranitidine hydrochloride (150 mg) administered twice a day for 5 days (n = 11), or no adjuvant treatment (n = 13). Blood monocyte and neutrophil chemotaxis and chemiluminescence were analyzed before the operation and on postoperative days 1, 3, and 9.

Monocyte chemotaxis to C5a in the 13 control patients was significantly decreased on day 1 compared with day 0. Chemotaxis in the 11 ranitidine-treated patients increased significantly from day 0 to day 1 (P < .01 between groups). Neutrophil chemiluminescence to zymosan and N-f-methionyl-leucyl-phenylalanine was significantly increased in control patients on day 1 compared with day 0 (P < .05), while ranitidine reduced chemiluminescence to zymosan insignificantly on day 1 (P < .07 between groups). Five of the 13 control patients developed postoperative infectious complications, which were related to decreased monocyte chemotaxis to C5a and increased neutrophil chemiluminescence to zymosan, compared with noninfected patients. A significant difference (P < .05) in chemiluminescence to zymosan between infected and noninfected control patients was observed on day 3 before clinical signs of infectious disease could be detected. There were no infectious complications in ranitidine-treated patients.

These results support previous studies on the effect of ranitidine to improve postoperative immunosuppression.