Methadone - Effects on the Body

Effects on the Body

Taken by mouth in pill, biscuit, or liquid form, methadone passes into the digestive system and from there is broken down in the liver. The liver releases the drug into the bloodstream, and it is carried to the brain and spinal cord, where it attaches to opiate receptors.

When no drugs are in the brain, opiate receptors 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., two brain chemicals that regulate feelings of well-being, overall motor coordination, breathing and coughing, and moods. Opiates replace these natural chemicals quickly and in such quantity that the user experiences a rush of pleasurable sensations and a calm drowsiness for hours afterward. This is the "high" that opiate users seek.

No "Rush" with Methadone

When methadone is introduced to the opiate receptors, it does not cause the rush of pleasure that other opiates and painkillers do. Its onset is slower, and it stays in the brain and body longer. Users may feel drowsy and relaxed. Any kind of pain will gradually cease, and it will not return as long as the user takes regular, carefully prescribed doses of the drug. As the dose of methadone leaves the brain and body—generally in about twenty-four to thirty-six hours—the user will begin to feel the discomfort of withdrawal unless a new dose is taken.

Alternative to Methadone

Beginning in the early twenty-first century, the U.S. Food and Drug Administration (FDA) approved trials on a drug called buprenorphine (marketed as Buprenex, Subutex, and Suboxone). A painkiller used in Europe to treat opiate addiction, buprenorphine works the same way as methadone without some of the complications of methadone treatment. The drug has similar effects on the body as methadone but it is not as addicting as other opiate or opioid-like drugs. In its Suboxone form, it contains naloxone, a drug that rids the body of opiates. Scientists are optimistic about the possibilities of Suboxone because grinding it up and snorting or injecting it will simply release the naloxone and cause withdrawal symptoms rather than a high.

In other parts of the body, methadone causes the same symptoms as other opiates and opioids. It inhibits the muscles in the bowels, leading to constipation, and works as a cough suppressant. If taken improperly, it can also affect breathing and lead to asphyxiation—the inability to breathe, which results in death.

Dr. Warren Bickel displays a sample of buprenorphine, a painkiller used to treat opiate addiction. Buprenorphine works the same way as methadone, but is not believed to pose the risk of an overdose. Photo by Jordan Silverman/Getty Images.
Dr. Warren Bickel displays a sample of buprenorphine, a painkiller used to treat opiate addiction. Buprenorphine works the same way as methadone, but is not believed to pose the risk of an overdose. Photo by Jordan Silverman/Getty Images.

Users may also experience nausea and loss of appetite, dry mouth that can lead to tooth decay and gum disease, and pinpoint pupils leading to sensitivity to light. Methadone may also lessen sexual function and desire.

At the end of methadone treatment, users must taper doses slowly to allow all the bodily systems to return to normal. A sudden end to methadone use brings on diarrhea, anxiety, insomnia, and flu-like symptoms.