The influence of meprobamate on heart rate in the conscious dog

The effects of meprobamate on heart rate in the unanesthetized dog were compared under two experimental conditions: (1) In the animal equipped with a telemetry device, in which the heart rate was on average 70/min over a 24 hour period, i.v. injection of 20 mg/kg of meprobamate tended to increase heart rate, a dose of 50 mg/kg provoking a significant tachycardia; (2) In the untrained dog restrained on a table, in which the heart rate ranged from 100 to 110/min, i.v. doses of 20 and 30 mg/kg of meprobamate did not lower heart rate, notwithstanding a significant sedative effect whereas a dose of 50 mg/kg provoked tachycardia; atropine-induced cardio-acceleration was not influenced by these doses of meprobamate.