Methadone is available as 5 mg, 10 mg, and 40 mg tablets
and as an oral solution. It is also available for subcutaneous (SQ) and
intramuscular (IM) injection.
How It Works
Methadone works on parts of the brain and
spinal cord to block the "high" caused by using opiates (such as heroin). It
also helps reduce cravings and withdrawal symptoms caused by opiate use. The
action of methadone is similar to other synthetic (man-made) medicines in the
morphine category (opioids). Substances that are derived directly from the
opium plant (such as heroin, morphine, and codeine) are known as
Why It Is Used
Methadone is commonly used to treat
addiction to opiates (such as heroin). Taken once a day, methadone eases opiate
withdrawal for 24 to 36 hours, decreasing the chance of relapse.
How Well It Works
As a treatment for opiate addiction,
methadone reduces the cravings and withdrawal symptoms caused by opiate use by
blocking the "high" and preventing the intense euphoric rush of these drugs.
This effect allows people to avoid the physical and psychological highs and
lows caused by changing levels of opiates in the blood, decreasing the chance
of relapse. In some cases of opiate addiction, methadone treatment may be
needed for several years or longer.
Methadone causes many side effects,
- Feelings of elation (euphoria).
- Difficulty urinating.
- Constipation, which may be severe.
- Talk with your doctor about
laxative use to prevent constipation.
prevent constipation at home. Make sure you drink
enough fluids. Most adults should drink between 8 and 10 glasses of water or
noncaffeinated beverages each day. Include fruits, vegetables, and fiber in
your diet each day.
Skin reactions, such as irritation, itching, or
See Drug Reference for a full list of side effects. (Drug
Reference is not available in all systems.)
What To Think About
Methadone is a long-acting medicine
and each dose stays in the body for a long time. For this reason dosages should
be adjusted with caution, ideally by an addiction specialist. It may take a
couple of days after the medicine is started before the dose of methadone is
In some people methadone impairs balance,
coordination, or the ability to think. Do not drive or operate any type of
equipment if you are taking methadone.
Do not drink alcohol or use
other drugs while you are taking methadone.
Methadone can interact
with many other medicines. Make sure that your doctor is aware of
all of the medicines that you are taking.
Methadone should be used
during pregnancy only if the benefits to the mother outweigh the risks to the
fetus. Talk with your doctor before using methadone if you are or
may be pregnant. This medicine can pass through your body in breast milk and
should be avoided while you are breast-feeding.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.