Haemodynamic responses to nicardipine in humans anaesthetised with halothane

The haemodynamic effects of an infusion of nicardipine were studied noninvasively before, during and after halothane anaesthesia in man, using a simple technique to achieve constant plasma drug concentrations. Eighty patients were randomly allocated to receive an intravenous infusion of either nicardipine or normal saline. Systolic and diastolic arterial pressures were significantly lower and heart rate significantly higher throughout the infusion than before infusion (p less than 0.001, all variables) in those patients who received nicardipine. The hypotension induced by nicardipine was not affected by induction of anaesthesia; halothane significantly reduced the nicardipine-induced tachycardia (p less than 0.001). Nicardipine caused no cardiac rhythm disorders. This technique for the intravenous administration of nicardipine achieves appropriate stable plasma concentrations, is devoid of severe haemodynamic disturbance and appears to be safe to use during halothane anaesthesia in patients with normal left ventricular function.