Cardiovascular effects of morphine in patients with coronary arterial disease

Large doses of morphine sulfate have been reported to cause myocardial lactate production and reduction in coronary blood flow in animals. Similar effects with clinical doses in man would significantly alter the management of cardiac patients. Eleven adult patients with significant coronary arterial disease and normal left ventricular ejection fraction were studied before and 30 minutes after infusion of morphine (0.25 mg/kg IV). Evaluation of myocardial metabolism showed an increase in coronary sinus oxygen content (p less than 0.001) and a reduction in myocardial oxygen consumption. Myocardial lactate extraction was not altered. No change in coronary sinus blood flow was seen. It is concluded that infusion of morphine sulfate, 0.25 mg/kg IV, does not produce global myocardial ischemia in patients with coronary artery disease and normal ventricular function.