What is methadone?

Methadone is an opioid medication. An opioid is sometimes called a narcotic. Methadone reduces withdrawal symptoms in people addicted to heroin or other narcotic drugs without causing the “high” associated with the drug addiction.

Methadone is used as a pain reliever and as part of drug addiction detoxification and maintenance programs and is only available from certified pharmacies.

Important information

You should not use methadone if you have severe asthma or breathing problems, or a bowel obstruction called paralytic ileus.

Methadone can slow or stop your breathing, especially when you start using this medicine or whenever your dose is changed. Never use this medicine in larger amounts, or for longer than prescribed. This medicine may be habit-forming, even at regular doses. Never share this medicine with another person, especially someone with a history of drug abuse or addiction. Keep the medication in a place where others cannot get to it.

Methadone may cause a life-threatening heart rhythm disorder. Call your doctor at once if you have a headache with chest pain and severe dizziness, and fast or pounding heartbeats.

Methadone is available only from a certified pharmacy.

Before using methadone

You should not use methadone if you are allergic to it, or if you have:

• severe asthma or breathing problems; or
• a bowel obstruction called paralytic ileus.

Methadone may cause a life-threatening heart rhythm disorder. Your heart function may need to be checked during treatment.

To make sure this medicine is safe for you, tell your doctor if you have:

• heart disease, or heart rhythm disorder;
• personal or family history of long QT syndrome;
• an electrolyte imbalance (such as low levels of potassium or magnesium in your blood);
• any type of breathing problem or lung disease;
• a history of head injury, brain tumor, or seizures;
• a history of drug abuse, alcohol addiction, or mental illness;
• liver or kidney disease;
• urination problems; or
• problems with your gallbladder, pancreas, or thyroid.

It is not known whether methadone will harm an unborn baby. If you use this medicine while you are pregnant, your baby could become dependent on the drug. This can cause life-threatening withdrawal symptoms in the baby after it is born. Babies born dependent on habit-forming medicine may need medical treatment for several weeks. Tell your doctor if you are pregnant or plan to become pregnant.