Antagonism of the cardiovascular effects of ketamine by diazepam in volunteers.

In healthy volunteers pretreated with atropine (0.5 mg), ketamine given as a bolus i.v. injection (2 mg/kg) followed by an infusion of ketamine (1 mg/kg/hr) for one hour, caused a significant rise in blood pressure and heart rate. This cardiovascular stimulation was rapidly counteracted by diazepam (0.2 mg/kg i.v.) given when the response to ketamine was already maximal.