Peripheral Vascular Effects of Morphine in Patients Without Pre-Existing Cardiac Disease

The effect of doses of morphine (10 mg/70 kg) on the forearm blood flow and vascular resistance was evaluated in 10 adults. The present findings were correlated with the central haemodynamic changes observed previously. Consistent and significant increases in forearm blood flow and significant decreases in forearm vascular resistance were observed in all patients. The pharmacological actions of morphine on the peripheral vascular system have been reported by numbers of workers and although the results of the studies are conflicting, the majority indicate that morphine has a dilating effect on peripheral vessels. Most of the information concerning the peripheral vascular effects of morphine has been derived from experimental animals and the varying results of reported investigations may be attributed, at least in part, to species differences. Thus, in dogs anaes-thetized with chloralose, Henney and colleagues