Signs, Symptoms & Side Effects of Methadone Abuse

Last Updated: October 27, 2022

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Methadone is a synthetic opioid that is used in the treatment of heroin addiction and as an analgesic, or pain reliever. Although methadone belongs to the family of opioids that includes heroin, it has a more gradual mode of action relative to heroin and does not produce a euphoric high like heroin.

Methadone has been used for forty years to alleviate the withdrawal symptoms due to heroin addiction and suppressing cravings for heroin and other opioids. However, the increased availability of methadone has resulted in the misuse and abuse of this drug in recent years.

Some of the side effects of the acute use of methadone include life-threatening effects including respiratory and cardiac changes that may prove fatal. Long-term use of both prescription and illicit methadone can result in the development of addiction.

Article Overview

  • Methadone is used in the treatment of heroin addiction because of its gradual mode of action and the absence of euphoric effects in individuals with opioid use disorder at therapeutic doses.
  • Misuse of prescription methadone or abuse can lead to an overdose.
  • Some of the adverse effects caused by methadone include sweating, itchiness, respiratory depression, seizures and even death.
  • Long-term use of methadone can lead to the development of drug tolerance and physical dependence on the drug. Methadone offers similar potential for abuse.
  • The dependence on methadone may be severe enough to cause addiction, characterized by an inability to control drug use and negative effects on interpersonal relationships.
  • Treatment for methadone addiction may involve both medications and behavioral approaches.
  • Treatment for methadone addiction involves detoxification at a medical detox, followed by treatment at a rehab to address issues underlying drug abuse.

Signs of Methadone Abuse

The signs of methadone abuse are similar to those observed with other opioids. Some of these signs include:

  • Increased drowsiness
  • Constriction of pupils
  • Confusion and hallucinations
  • Constipation
  • Vomiting
  • Nausea
  • Dry mouth
  • Mood changes
  • Decreased heart rate and blood pressure
  • Problems with vision
  • Sexual dysfunction

Symptoms of Methadone Addiction

Some of the symptoms of methadone addiction include:

  • Intense cravings for methadone
  • Use of larger amounts of opioids or for a longer duration than intended
  • Inability to control or reduce methadone use
  • Negative consequences on interpersonal relationships and social life due to methadone use
  • Failure to fulfill obligations at work or in social life
  • Reduced participation in social and work-related activities

How Methadone is Abused?

Methadone is available in the form of a tablet, oral solution or liquid form for injection. Methadone is generally safe when taken for a short period and as prescribed by a doctor. But even when prescribed by a doctor, methadone use can occasionally cause life-threatening adverse effects.

Misuse of prescription opioids can result in the development of dependence and addiction to methadone. Examples of such misuse include intake of larger doses, using a different route of administration or use of the drug for a longer duration.

Individuals seeking treatment for heroin addiction may be prescribed methadone and may ultimately tolerance and dependence on methadone if used for a long duration. Methadone may also commonly be abused because of its euphoric effects at high doses.

Methadone Abuse Facts & Statistics

Some key facts and statistics on methadone abuse:

  • In 2015, 5,590 hospitalizations occurred due to non-fatal methadone overdose occurred at a rate of 1.1 per every 100,000 hospitalizations. Methadone was responsible for  3,709 emergency department visits in 2015 at a rate of 1.1 per 100,000 emergency room visits.
  • Methadone toxicity was responsible for 3,373 deaths in 2016 at a rate of 1 per 100,000 deaths.
  • According to the 2017 National Survey on Drug Use and Health, 261,000 (0.1%) individuals over the age of 12 had misused methadone in the year prior to the survey.

How Addictive is Methadone?

Although methadone is often used for the treatment of dependence on heroin, methadone itself has high addiction potential. The abuse potential of methadone is similar to other opiates, including morphine and oxycodone.

Long-term use of methadone can lead to the development of dependence and tolerance on the drug. Tolerance to methadone is often characterized by the necessity to take larger amounts of the drug to attain the previously experienced effects. Dependence involves the necessity to use methadone to function normally.

Even weaning one’s self off of methadone can bring risks. Abstinence from methadone use after long-term use often results in withdrawal symptoms that involve muscle and bone pain, diarrhea, vomiting, abdominal cramps, sleep disturbances and intense cravings. These withdrawal symptoms can be very severe, proving to be major obstacles for individuals attempting to overcome drug use.

Side Effects of Methadone  Abuse

Methadone is more easily available relative to heroin or oxycodone and may be used as a substitute for these drugs. However, methadone does not produce the high as the other drugs and may be used in large amounts leading to an overdose. An overdose may involve cardiac and respiratory toxicities and may lead to death.

Short Term Effects

Some of the short-term effects of methadone abuse include:

  • Dizziness
  • Nausea
  • Vomiting
  • Sleepiness
  • Itchiness
  • Constipation
  • Restlessness
  • Increased sweating
  • Sexual dysfunction including impotence in men
  • Menstrual irregularities in women

Some of the more severe effects of methadone use include:

  • Rash and hives
  • Contraction of the pupils
  • Severe respiratory depression – slow and abnormal breathing that can lead to respiratory failure
  • Pulmonary edema or accumulation of fluids in the lungs
  • Decreased heart rate and blood pressure
  • Reduced muscle tone
  • Seizures
  • Coma
  • A methadone overdose can lead to death

Use of methadone with other medications such as benzodiazepines or substances such as alcohol can potentiate the adverse effects of methadone.

Long Term Effects

There are a number of long-term side effects of methadone abuse that should be considered in assessing the full impact.

  • Long-term use of methadone can lead to the development of tolerance and dependence.
  • The dependence may be severe enough resulting in methadone addiction characterized an inability to control drug use despite negative consequences on social life.
  • Long-term methadone use for pain relief can lead to chronic persistence of pain and may even result in the worsening of pre-existing pain.
  • Chronic use of prescription opioids like methadone is associated with an increased risk of mood disorders including depressive and anxiety disorders.
  • Long-term use of methadone is associated with an increased risk of arrhythmia.
  • Chronic use of methadone may also lead to various lung and respiratory disorders.

How To Get Help for Methadone Addiction

Treatment for methadone addiction generally involves behavioral therapy and medications. Medications used for the treatment of methadone addiction may involve the use of buprenorphine and naltrexone.

Buprenorphine also binds to opioid receptors with a larger affinity for the receptor than methadone while exerting only weaker physiological effects. Buprenorphine has been found to potentially help alleviate the symptoms of methadone withdrawal and reduce cravings.

As another option, Naltrexone blocks the opioid receptors to which methadone binds and can help prevent relapse to methadone use. The use of naltrexone requires full detoxification – the complete removal of the drug from the body. Initiation at an earlier stage can lead to very severe withdrawal symptoms. These medications can help to overcome methadone addiction only when combined with behavioral approaches. This behavioral therapy may involve cognitive behavioral therapy, motivational enhancement therapy and contingency management. Cognitive-behavioral therapy involves the identification of thoughts and behaviors that lead to drug use and learning coping strategies to resist drug use.

Motivational enhancement therapy also can involve increasing the individual’s motivation to engage in treatment to overcome drug use. Contingency management involves the use of positive reinforcement in the form of gift vouchers or other rewards in exchange for abstinence from drug use.

Enrollment in a methadone treatment center or rehab is often necessary for the treatment of addiction to prescription opioids like methadone. In the cases of severe dependence on methadone, the general path of treatment involves enrollment in medical detox to help the individual cope with the withdrawal symptoms, followed by therapy at an inpatient or residential rehab. Following treatment at an inpatient rehab facility, behavioral therapy at an outpatient rehab and participation in support groups is essential to avoid a relapse.

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