Influence of Cimetidine on Cardiovascular Parameters in Man

Abstract

Cardiac output was measured in 10 patients using the dye dilution method, before and after the intravenous injection of 400 mg cimetidine. The subjects were in the intensive care unit and required intermittent positive pressure ventilation. There was no change in the average blood pressure, heart rate and cardiac output during the 60 minutes following the cimetidine, although one patient showed a marked fall in cardiac output. The results suggest that cimetidine is without a marked depressant effect on cardiovascular system.

Haemodynamic effects of H2‐receptor antagonists

“…In the patients studied, heart rate and sinus node function were not altered. Samuel & Dundee [75] reported a fall in blood pressure (20 mmHg systolic) and cardiac output (30%) using the Hamilton-Steward dye dilution method 5 min after administration of cimetidine in one of 10 patients tested. Barbat & Warrington [76] noted a reduction in heart rate following oral cimetidine treatment whereas ECG, systolic time intervals (STI), and blood pressure were unaffected.…”

“…For example, catecholamines or other vasoactive substances were administered to patients in some of these studies [79,81,82,85]. In other investigations, only partial information about concomitant treatment in these critically ill patients was presented [75,83]. Furthermore, the very presence of a patient in an intensive care unit implies a maximum sympathomimetic stimulation leading to a non-negligible alteration of cardiac function.…”

“…Furthermore, the very presence of a patient in an intensive care unit implies a maximum sympathomimetic stimulation leading to a non-negligible alteration of cardiac function. Therefore, haemodynamic results obtained in patients in intensive care units [75,79, are difficult to compare with data obtained from healthy subjects [76][77][78]80,. A comparison of studies is also hindered by the variety of non-invasive or invasive methods used for measuring cardiac function.…”

“…A decrease in blood pressure after intravenous cimetidine administration has been noted most frequently [75,. In some studies, the fall in blood pressure induced by cimetidine was accompanied by an increase in heart rate [78,81].…”