Morphine - Effects on the Body

Effects on the Body

Morphine floods a group of receptors in the brain and spinal column that take in endorphinsA group of naturally occurring substances in the body that relieve pain and promote a sense of well-being. and enkephalinsPronounced en-KEFF-uh-linz; naturally occurring brain chemicals that produce drowsiness and dull pain.. Biologists think that endorphins and enkephalins work together naturally to dull pain or to ease anxiety when someone is hurt or close to death. Morphine replaces these natural molecules, and in a much greater quantity than the body can supply. Pain signals surging from an injury or a cancerous tumor cannot relay their messages to the brain because morphine has blocked the receptors that register the pain, while rewarding the receptors that enhance pleasure. Patients may still hurt, but the pain will not bother them as much, and they will be able to concentrate on other aspects of life.

Not Typically Abused for a High

Morphine is not as fat soluble as heroin, so even when injected it does not produce the instant rush of pleasure that makes heroin attractive as an abused drug. Nevertheless, morphine does induce a dreamy state of happiness, drowsiness, and relief from anxiety that can last from four to six hours, depending on the dose and the way it was administered. Most people taking morphine for pain learn to live with the drowsiness and confusion. Some opt to live with the pain instead so that their senses are not dulled by the drug. Usually patients will work closely with their doctors to monitor doses so that a balance can be achieved.

Scientists are finding that patients in pain can become tolerant to very high doses of morphine—doses that, if taken recreationally, would kill a person outright. Tolerance, or needing higher doses of a drug to achieve the same results, is a standard side effect of opiate use.

All opiates produce similar side effects in the body. Morphine users will typically develop constipation because the drug slows muscle movement in the bowels. Breathing may be slowed as well. The drug can affect coordination—users must adjust to the medicine before driving or operating machinery. Other side effects include nausea and vomiting, loss of appetite, loss of sexual function, and pinpoint pupils. Some people develop a mild allergic reaction in the skin that causes itching or prickling.

Even when used as directed, morphine can cause withdrawalThe process of gradually cutting back on the amount of a drug being taken until it is discontinued entirely; also the accompanying physiological effects of terminating use of an addictive drug. symptoms if a dose is missed or the medication is stopped suddenly. These symptoms include sneezing, runny nose, muscle aches, insomnia and anxiety, diarrhea, muscle twitching, sweaty and clammy skin, and goose bumps.