Dose-response studies on glycopyrrolate and atropine in conscious cardiac patients

The dose-heart rate response relationship for the two anticholinergics, atropine and glycopyrrolate, were studied in non-anaesthetised patients about to undergo coronary artery surgery. Two methods were used, the administration of increasing doses to different groups of patients, and an incremental dose technique in the same patient. Both drugs increased heart rate in a dose-related manner with glycopyrrolate being approximately twice as potent as atropine. Glycopyrrolate is as effective as atropine in correcting bradycardia prior to open heart surgery.