Morphine is a powerful opiate that is used medically to treat pain and other conditions. It is also abused to achieve a high or avoid withdrawal symptoms. The body has opioid receptors throughout the body and each receptor reacts specifically in response to that part of the body. Morphine activates the delta and kappa opioid receptors in the heart, resulting in several effects. Morphine in the use of surgery and anesthesia can be very beneficial to patients during and after treatment. It can also have deadly consequences as it is capable of stopping the heart when taken in high doses.
Reduces Cardiac Inflammation
One of the beneficial effects of morphine is its anti-inflammatory properties. This can be effective for patients with inflammation of the heart. Morphine can be used to treat acute heart infections that cause inflammation, while antibiotics or anti-virals work to eliminate the infection. Some heart patients have long-term chronic inflammation of the heart due to repeated stress, high blood pressure, heart disease and excessive workload from cholesterol and plaque build up. In this case, morphine may be used to prevent further inflammation during corrective surgery, such as cardiopulmonary bypass. The sixth edition of "Clinical Anesthesia" states that morphine is highly beneficial at reducing inflammation in the heart during surgery and is helpful as well in preventing post-operative hypothermia.
Heart disease is the leading cause of death in the U.S. and many patients suffer damage to the heart after corrective surgery. Heart disease often involves a condition known as ischemia, in which a significant reduction of blood flow is available to the heart, usually due to cholesterol blockage. When blood flow returns to those portions of the heart, additional inflammatory and oxidative damage can occur, known as reperfusion. Morphine can be used to protect heart patients both before and after surgery by preventing damage caused by ischemia and reperfusion. In a study in the April 2008 issue of the "Journal of Surgical Research," Dr. Zuolei Chen and associates found that conditioning the heart with morphine before or after an ischemic episode considerably reduced the amount of tissue damage, known as infarction.
Chest Pain Relief
Morphine is a highly effective pain killer and some health professionals use it to help alleviate serious chest pains during angina or heart attacks. Although it helps in dilating the blood vessels around the heart, it can also cause low blood pressure which can further worsen the damage caused during a heart attack. In some instances of heart attack, morphine may only mask the pain, allowing further damage to occur without the patient receiving important pain signals to the brain. Dr. Trip Meine and fellow researchers at the Duke Clinical Research Institute reported that heart attack patients treated with morphine had a 48 percent higher risk of dying and a 38 percent higher risk of suffering another heart attack while in the hospital. They recommend nitroglycerin as the first choice of treatment due to its higher safety outcomes.
- "Clinical Anesthesia, Sixth Edition"; Paul Barash et al; 2009
- U.S.. Centers for Disease Control: Leading Causes of Death
- "Journal of Surgical Research"; Morphine Postconditioning Protects Against Reperfusion Injury in the Isolated Rat Hearts; Zuolei Chen et al; April 2008
- "Anesthesia & Analgesia"; Morphine-Induced Analgesia, Hypotension, and Bradycardia Are Enhanced in Hypertensive Rats; Bradley Taylor et al; June 2004