Methadone: Uses, Side Effects, and Addiction

Methadone is an opioid analgesic medicine used to treat opioid use disorder (OUD) and is prescribed for chronic pain. Methadone helps reduce cravings and withdrawal symptoms of opioids by activating a controlled amount of opioid receptors in the brain. Healthcare specialists prescribe methadone during the early stage of treatment to overcome the physical symptoms of opioids. Methadone reduces the death rate due to opioid overdose, according to research titled โMethadone Matters: What the United States Can Learn from the Global Effort to Treat Opioid Addiction,” published in 2019 by the National Library of Medicine. Methadone helps individuals overcome the negative effects of opioids and helps them return to normal life.
The main uses of methadone are to treat chronic pain and opioid use disorder. It is used to help individuals recover from cravings, euphoria, and withdrawal symptoms of opioid addiction. Methadone is prescribed as a painkiller for individuals with chronic pain like neuropathic and cancer pain.
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The risks and side effects of methadone are drowsiness, vomiting or nausea, sweating, constipation, chest pain, dizziness, chest pain, respiratory depression, slow breathing, hallucinations, itchy skin, and cardiac issues. These side effects depend on the duration of use, amount of dose, and individualโs health.
What is Methadone?
Methadone is a synthetic opioid used as a medicine to treat opioid use disorders (OUD) and chronic pains. Methadone works as a mu-opioid receptor (MOR) in the brain that fights against the drugs, minimizing the cravings and withdrawal symptoms of opioid addiction. Methadone is given in the range of low (1 mg to 39 mg), medium (40 mg to 59 mg) and high (60 to 109 mg) dosages. Methadone is considered a Schedule II controlled substance, which means it has a high chance of drug abuse that leads to dependency. Methadone is used to treat severe to moderate pain during neuropathy and cancer if individuals do not respond to non-opioid medications, according to research titled “Methadone,” published in 2024 by the National Library of Medicine.
Methadone is structurally different from other opioids like morphine and codeine. These opioids have three-ringed structures, but methadone consists of a linear structure that increases the duration of actions and pharmacokinetics. Methadone chemically belongs to a class of compounds called diphenylheptane. Methadone is recommended in opioid agonist therapy to minimize the effects of opioids, as shown in research titled โManagement of opioid use disorder: 2024 update to the national clinical practice guideline,โ published in 2024 by the Canadian Medical Association Journal.
How Common is Methadone?
Methadone is very common in the US because of the high rate of opioid use disorder (OUD). This is why methadone is recommended by the Food and Drug Administration (FDA) to reduce the overdose rate. Almost 81,806 individuals died because of opioid overuse in the US in 2022, according to a research titled โTreatment for Opioid Use Disorder: Population Estimates โ United States, 2022โ, published in 2024 by the US Centers for Disease Control and Prevention. Methadone without a prescription is banned in the US. Doctors only use it during opioid treatment and in chronic pain. In the past few years, the availability of methadone has increased because of an increase in opioid use disorder. In 2015, individuals receiving methadone treatment increased up to 21-25%, as shown in the research โTrends in the Use of Methadone, Buprenorphine, and Extended-release Naltrexone at Substance Abuse Treatment Facilities: 2003-2015 (Update),โ published in 2017 by the SAMHSA. Men aged between 35 and 49 receive more methadone medication than women.
How Does Methadone Work?
Methadone works by attaching to opioid receptors in the brain to eliminate the side effects of opioids like cravings, anxiety, hallucinations, and withdrawal symptoms. Methadone stimulates the mu-opioid receptors (MOR) that fight against substances like heroin, cocaine, and fentanyl. Methadone performs its actions very slowly and prevents feelings of euphoria. Doctors have used methadone for almost 40 years to treat opioid addiction, according to a research titled โHow do medications to treat opioid use disorder work?โ published in 2021 by the National Institute on Drug Abuse. It has a long half-life which is why it stays in the blood for 8 to 59 hours. Steady levels of methadone in the bloodstream help to minimize the cravings and withdrawal effects of opioid use disorder.
What are the Uses of Methadone?
The uses of methadone are to treat opioid addiction and chronic pain by stimulating the mu-opioid receptors (MOR) in the brain. Methadone is used in opioid treatment called medication-assisted treatment (MAT). Methadone causes a reduction in the intense feelings of pleasure caused by heroin and fentanyl which helps in reducing the negative effects of opioid addiction. Methadone is used in OTPs under proper surveillance. It is also used to treat moderate to severe pain during cancer and neuropathy pain. Methadone is prescribed to treat pain when other non-opioid drugs do not show any positive outcome in patients. Methadone is used under the supervision of doctors to protect individuals from addiction.
How is Methadone Consumed?
Methadone is consumed as tablets, oral tablets dispersible, injections, oral liquid, and powder. Oral tablets are swallowed directly and are available in a range between 5 mg and 40 mg. Methadone dispersible tablets are consumed by dissolving into liquids like fresh juices or water and are used for opioid treatments. The oral liquid contains 10 mg of methadone per milliliter, it is prescribed by the doctors in the stabilizing phase. Professionals give methadone injections to treat moderate to severe pain. Methadone injections are also used in OTPs when individuals are unable to take oral liquids. Powdered methadone increases the analgesic effects and slows down the symptoms of drug overdose. The powder is given to individuals with life-threatening symptoms like respiratory depression.
What are the Medical Benefits of Methadone?
The medical benefits of methadone are treating opioid use disorder (OUD) and minimizing chronic pain during neuropathy and cancer. Methadone reduces the risk of opioid addiction. Methadone attaches to the binding site of opioid receptors in the brain which reduces the withdrawal symptoms of other opioids and eliminates cravings. Methadone performs its actions without producing the feeling of euphoria. Methadone maintenance therapy (MMT) is an effective long-term recovery program that reduces the risk of opioid overdose in individuals and pregnant women, according to a research titled โMedication-Assisted Treatment With Methadone: Assessing the Evidence,โ published in 2014 by Psychiatry Online. Long-term treatment therapy of methadone helps individuals to overcome opioid symptoms without relapse. These therapies decrease the rate of substance abuse by up to 23.9%, as shown in the research โA systematic review and meta-analysis of the efficacy of the long-term treatment and support of substance use disorders,โ published in 2021 by ScienceDirect.
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What are the Risks and Side Effects of Methadone?
The risks and side effects of methadone are restlessness, nausea or vomiting, itchy skin, hives or a rash, heavy sweating, constipation, sexual problems, difficulty breathing or shallow breathing, feeling lightheaded or faint, swelling of the face, lips, tongue, or throat, chest pain, fast or pounding heartbeat, and hallucinations.
The 12 risks and side effects of methadone are listed below:
- Restlessness: Restlessness is the behavioral side effect of methadone that occurs during the early stage of treatment therapy. Methadone increases the risk of damaging the central nervous system, leading to fatigue and restlessness. Restlessness disturbs the individual’s mental health and causes instability and discomfort.
- Nausea or Vomiting: Nausea or vomiting is one of the physical side effects of methadone that occurs in the initial treatment days. Doctors eliminate these effects by adjusting the dose. Sometimes these side effects last throughout the treatment.
- Itchy skin, rashes, or hives: Itchy skin, hives, or rashes are the physical side-effect of methadone. Methadone releases a chemical, histamine, in the body that causes itchiness and rashes. Individuals can be allergic to methadone which enhances the risk of rashes or itchy skin. The adverse reaction of methadone also causes severe itchiness, according to a research titled โAllergic Reactions From Injectable Methadone,โ published in 1999 by The American Journal of Psychiatry.
- Heavy sweating: Heavy sweating is a physical side effect of methadone due to increased body temperature. Methadone affects a part of the brain called the hypothalamus which maintains the temperature by osmoregulation, causing heavy sweat. Sweating is an adverse reaction of methadone that affects almost 45% of individuals, as shown in research titled โMethadone-Induced Hyperhidrosis Treated With Oxybutynin,โ published in 2017 by PubMed Central.
- Constipation: Constipation is the side effect of methadone. Methadone stimulates the opioid receptors in the brain that cause gastric issues such as constipation. The absorption of liquids increases due to gastric emptiness causing a decrease in fluid levels in the small intestine. The low fluid level leads to constipation, according to a research titled โOpioid-Induced Constipationโ published in 2023 by StatPearls.
- Sexual problems: Sexual problems are the psychological side effect of methadone that reduces testosterone and libido. Methadone suppresses the hormone called gonadotropin-releasing hormone (GnRH) which helps the production of sex hormones. Methadone maintenance therapy (MMT) is a long-term treatment program of up to months and years that affects hormone production and causes sexual problems.
- Shallow breathing: Shallow breathing is the risk of methadone that causes life-threatening problems. Methadone causes severe respiratory depression which leads to slow and shallow breathing problems. Methadone drops the oxygen level in the body which causes slow breathing.
- Feeling lightheaded or faint: Low blood pressure leads to fainting or dizziness which is a risk of methadone. Individuals feel light-headed because of the methadone depressant effect on the central nervous system. Individuals with a medical history of hypotension are at higher risk of fainting.
- Swelling of the face, lips, tongue, or throat: Swelling of the face, lips, tongue, or throat is a risk of methadone that occurs due to allergies and severe reactions to methadone. The severe allergic reaction of methadone causes angioedema which is the swelling of the face, lips, throat, or tongue. The physical side effect of methadone causes a life-threatening problem called anaphylaxis and individuals need oxygen support in OTPs.
- Chest pain: Chest pain is a risk factor of methadone that leads to heart problems. Methadone affects the cardiovascular system which leads to severe chest pain. Methadone reduces the oxygen level in the body which leads to slow breathing that causes discomfort and chest pain. Consuming methadone with other drugs affects respiratory function and leads to severe chest pain.
- Fast or pounding heartbeat: Fast or pounding heartbeat is a risk factor for methadone. The change in heartbeat rhythm and blood circulation due to methadone causes fluttering and racing of the heart. Methadone prolongs the QT interval on an ECG and causes an increase in the heartbeat. The prolongation occurs when the dose is higher than 60 to 120 mg per day, according to a research titled โQT Interval Screening in Methadone Maintenance Treatment: Report of a SAMHSA Expert Panel,โ published in 2014 by PubMed Central.
- Hallucinations or confusion: Hallucinations are the psychological risks and side effects of methadone that occur due to overdose and high doses during treatment. Methadone disturbs the functioning of the brain which leads to cognitive impairment like confusion. Methadone stays in the body for 8 to 59 hours because of its long half-life which increases the risk of methadone overdose and leads to confusion and hallucinations.
How Does Methadone Use Lead to Addiction?
Methadone use leads to addiction by taking high doses of the medicine without a prescription. Methadone is a Schedule II controlled substance which means it has a high potency of physical and psychological dependency. Methadone has a long half-life so it stays in your system for a longer period and slowly produces feelings of pleasure, and euphoria which cause addiction. Taking methadone more than the recommended amount leads to methadone addiction. Individuals who use methadone to minimize the withdrawal system of other opioids are at high risk of methadone abuse.
Can you Overdose on Methadone?
Yes, you can overdose on methadone when use more than prescribed amounts or consume methadone without supervision. Methadone overdose is life-threatening because of its long half-life as it stays in the body for a longer time than other opioids. Individuals mix methadone with other substances like heroin, benzodiazepines, and alcohol which increases the risk of overdose. During COVID-19, the death rate of methadone overdose increased in the United States. In 2020, the methadone overdose death rate was approximately 105.4 deaths per month, as shown in research โMethadone-involved overdose deaths in the United States before and during the COVID-19 pandemic,โ published in 2023 by PubMed. It is important to treat individuals with OUD under supervision otherwise, the use of methadone leads to addiction.
Does Methadone Get You High?
Yes, methadone gets you high because it releases the same opioid receptors like fentanyl or morphine in the brain that increase the feeling of euphoria. These feelings of joy, pleasure, and cravings are low in methadone as compared to other opioids because it is used as a medication. The risk of getting high, increases if methadone is used without a prescription. Methadone is a synthetic opioid so the risk of abuse is high if used without medical care. It stays in the body longer than other substances and affects their physical and psychological health. Individuals intentionally overdose on methadone to get the same feeling of happiness and joy as other opioids which causes addiction.
Can Methadone Interact With Other Drugs?
Yes, methadone interacts with other drugs like alcohol, or benzodiazepines that have the same effects and increases the risk of overdose and death. Methadone also interacts with drugs like sleeping pills, sedatives, pain relievers, or cough medicine. These sedatives cancel the effect of methadone and affect the central nervous system (CNS). Individuals consuming methadone with other drugs increase the risk of respiratory depression. Its effectiveness decreases when other antibiotics or antifungal medicines are consumed with methadone. Any drug that increases the chances of overdose, organ failure, coma, or respiratory depression should not be consumed with methadone.
What is more addictive, methadone or suboxone?
Methadone is more addictive because it releases more opioid receptors which enhances the feelings of pleasure, happiness, and euphoria as compared to suboxone. Methadone is a full opioid agonist which increases the risk of opioid use disorder. Suboxone is a partial opioid agonist which contains naloxone and buprenorphine. These chemicals stimulate the opioid receptors. The chances of addiction are low in suboxone because of the presence of buprenorphine. Buprenorphine reduces the effect of euphoria. Methadone dependency risk is high as compared to suboxone because individuals use methadone for the rest of their lives to minimize the craving for other opioids.
Is methadone addiction worse than heroin addiction?
No, methadone addiction is not worse than heroin addiction because the overdose-death ratio in heroin addiction is five times more than that of methadone addiction. Heroin increases the cravings, feelings of joy, happiness, and libido by activating the opioid receptors. Methadone is used in OPTs with prescription but heroin is an illegal drug that increases the rate of substance abuse. The risk of infectious diseases is also high with heroin use as compared to methadone. Methadone withdrawal effects are long-lasting because of its half-life but the feelings of euphoria are much higher in heroin which leads to heroin addiction.
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