Methadone is a type of opiate medication that is long-acting and may be used to treat drug addiction, according to the U.S. Department of Health and Human Services. Methadone shares many similarities with morphine. Methadone is available in liquid, powder, and tablet form, notes the Drug Policy Alliance. In addition to its use in treating drug addiction, methadone may also be used as a pain reliever. Nevertheless, long-term use can have unintended effects.
Addiction
Long-term use of methadone can cause addiction. Addiction may occur as a result of taking methadone at the wrong doses. Should this side effect develop, it is highly likely for withdrawal to occur should methadone use be stopped, notes the U.S. Department of Health and Human Services.
Appetite Loss and Nausea
Methadone use over a prolonged period may decrease appetite, notes Drugs.com. Appetite loss may also be accompanied by nausea and dryness of the mouth.
Breathing Problems
Prolonged methadone use can cause severe breathing problems, notes Drugs.com. This particular side effect can be lethal if not treated quickly.
Decreased Libido and Sexual Dysfunction
Long-term use of methadone can decrease the libido. In addition to libido reduction, methadone can cause impotence and may impede the ability to achieve orgasm, explains Drugs.com.
Diarrhea and Constipation
Methadone may cause diarrhea and constipation due to prolonged use. As such, eating fibrous food and staying properly hydrated is vital, according to the U.S. Department of Health and Human Services.
Increased Perspiration
Taking methadone over a long period of time may also cause the rate of perspiration to increase to excessive levels, notes the U.S. Department of Health and Human Services. Making subtle adjustments to the methadone dose may alleviate this side effect.
Insomnia
Methadone can cause insomnia. This side effect may continue even for several months after methadone treatment has stopped, notes the U.S. Department of Health and Human Services.
Mood Swings
Methadone use can lead to mood swings over time, notes the American Cancer Society. As such, the medication may cause states of euphoria and fits of depression to occur.
Passivity, Restlessness and State of Confusion
Long-term methadone use can lead to moments of passivity or state of sedation, explains the Drug Policy Alliance. This side effect may sometimes be alleviated by adjusting the dose of methadone being taken. Methadone can cause overall restlessness and a general sense of confusion, notes Drugs.com.
Weakness and Sleepiness
Methadone use can cause a general sense of weakness and sleepiness if used for over a long-term period, notes Drugs.com.
