Methadone is an opioid medication that is most typically used to treat narcotic addiction. It is a longer acting opioid than most Schedule I narcotics, such as heroin, and as such, methadone can relieve painful withdrawal symptoms without giving the person taking it a “high.” However, this does not mean that methadone is completely safe; there are some side effects that anyone taking this drug should be wary of.
Side Effects of Legitimate Use
Even when methadone is used appropriately (taking a minimal dose under the care of a doctor or addiction specialist), there are still a wide range of side effects that can occur. An individual should inform their doctor if they begin to experience these side effects, as they could become dangerous over time. These side effects include:
- Absent or irregular menstrual periods
- Blurred or loss of vision
- Decreased interest in sexual intercourse
- Redness, swelling, or soreness of the tongue
- Weight changes
- Hives or rash
Also, it is important to note that methadone is considered a Schedule II substance. This means that, while there are legitimate medical uses for the drug, there is also a high potential for abuse if it is misused. Individuals struggling with narcotic addiction may replace their former addiction with methadone, which can lead to troubling and illicit behavior. In many instances, treatment professionals may prefer to use Suboxone (a combination of buprenorphine and naloxone) for opioid maintenance treatment due to its lower abuse potential.
Abuse of Methadone
According to the National Highway Traffic Safety Administration, there are two major ways that a person can take methadone: oral ingestion (usually in a pill or drinkable liquid) and injection (which can be either intravenous, intramuscular, or subcutaneous). When a person abuses methadone by either of these methods, they risk many side effects, including overdose. Abusing liquid or tablet methadone can lead to shallow breathing, a weak pulse, muscle spasms, or even coma.
Taking methadone by injection holds many of the same risks; however, the act of injecting the drug leads to a variety of related risks that drinking it does not. For example, individuals who abuse methadone by injection are at an increased risk of contracting HIV or hepatitis C. Shooting methadone can also cause blood clots, as many of the fillers in drinkable or tablet methadone (e.g., glycerin, sorbitol, etc.) do not break down in the veins.
Physical Effects of Methadone Abuse
In addition to the most serious effects of methadone abuse, such as contracting serious illnesses or overdosing, more common side effects can also be uncomfortable and upsetting. For example, a 2007 study from the University of Wisconsin’s Department of Family Medicine reported that sexual dysfunction is a common side effect of methadone abuse for both men and women. This can lead to emotional problems between individuals and their partners, which can in turn create mental anguish that leads to further drug abuse.
Another common yet uncomfortable side effect of methadone abuse is gastrointestinal distress. The journal of Alimentary Pharmacology and Therapeutics found that 49 percent of individuals they surveyed in their 2008 study reported constipation because of long-term methadone use. Along with being very uncomfortable, this can lead to hemorrhoids, rectal bleeding, and other painful complications.
Mental Effects of Methadone Abuse
Methadone activates the opioid receptors in the brain, leading to cognitive changes that can be long-lasting. Memory loss, mood changes, and difficulty learning are common, as well as increased anxiety and depression. In fact, the Journal of the American Medical Association (JAMA) reports that “Methadone subjects perform … significantly poorer on several tests of learning and immediate recall compared to abstinent subjects.”
These side effects serve as an important reminder to individuals suffering from narcotic addiction that methadone is not a cure. While it can be key to the recovery process for many individuals, it must be used in conjunction with therapy to foster complete recovery.