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Methadone belongs to the group of drugs known as opioids.


Opioids are classed as depressant drugs as they work by slowing down the functions of the central nervous system. Alcohol, cannabis and benzodiazepines are examples of other depressant drugs. 


Methadone is manufactured and is used as a substitute for the treatment of people dependent on heroin and other opioids.

Its effects are much longer lasting than heroin, a single dose being effective for approximately 24 hours; the effects of heroin may only last for a couple of hours.

In a treatment program, methadone is usually given out in syrup form and drunk with cordial or fruit juice.


Other names

'done' or 'the done'


What it looks like

Methadone comes as a tablet, syrup or injection.


How is it used?

Generally, there are 2 types of methadone programs:

  • Maintenance or long-term programs. These may last for months or years, and aim to reduce the harms associated with drug use and improve quality of life.

  • Withdrawal (short-term) detoxification programs. These last approximately 5–14 days, and aim to ease the discomfort of coming off heroin.


Effects of methadone

The effects of any drug (including methadone) vary from person to person. How methadone affects a person depends on many things including their size, weight and health, also whether the person is used to taking it and whether other drugs are taken around the same time. The effects of any drug also depend on the amount taken.


Some people on methadone programs will experience unwanted symptoms during their treatment. These may be caused by the dosage they are receiving being too low or too high, which can occur particularly at the beginning of treatment. Some symptoms may also occur due to the side effects of the drug itself.

There is no safe level of drug use. Use of any drug always carries some risk—even medications can produce unwanted side effects. It is important to be careful when taking any type of drug.


Low dose

Symptoms of a methadone dose being too low may resemble having a bout of flu. They include:

  • runny nose, sneezing

  • abdominal cramps

  • feeling physically weak

  • loss of appetite

  • tremors

  • muscle spasms and jerking

  • goose bumps

  • tears

  • nausea/vomiting

  • yawning

  • diarrhoea

  • back and joint aches

  • high temperature but feeling cold

  • sweating

  • irritability, aggression, feelings of uneasiness

  • difficulty sleeping

  • cravings for the drug.


A person who suddenly stops taking methadone may experience many of the symptoms listed above. The withdrawal symptoms usually begin 1 to 3 days after the last dose, and peak around the 6th day, but can last longer.


High dose

Symptoms of too high a dose include:

  • drowsiness, nodding off

  • nausea, vomiting

  • shallow breathing

  • pinpoint pupils

  • low body temperatures

  • slow pulse

  • lowered blood pressure

  • heart palpitations

  • dizziness

  • problems with sexual functioning

  • poor blood circulation.


Other side effects

Some people may also experience certain side effects that are unrelated to the dosage, including:

  • sweating (clients should drink at least two litres of water per day to avoid dehydration)

  • constipation

  • aching muscles and joints

  • lowered sex drive

  • skin rashes and itching

  • sedation

  • fluid retention

  • loss of appetite, nausea, vomiting

  • abdominal cramps

  • tooth decay

  • irregular periods.


Side effects should decrease soon after the methadone program is completed. As with all opiates, methadone alone in its pure form will not cause any damage to the major organs of the body. Prolonged use will not cause any physical damage, apart from tooth decay. For those with pre-existing impaired liver function (following conditions such as hepatitis B, hepatitis C infection, or prolonged alcohol use), the methadone dose may require careful monitoring. People who are not dependent on opiates who take methadone will experience some of the short-term effects similar to those on a methadone program receiving too high a dose.


Other effects of methadone use

Taking methadone with other drugs

Deaths related to methadone only are rare. Methadone-related deaths are usually due to combining methadone with other drugs, particularly benzodiazepines and alcohol. 


Tolerance and dependence

People who use methadone regularly for a prolonged period can develop dependence and tolerance to it, which means they need to take more methadone to get the effect they are used to having. Dependence on methadone can be psychological, physical, or both. They crave the drug and find it very difficult to stop using it. Physical dependence occurs when a person’s body adapts to methadone and gets used to functioning with the methadone present.


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