Methadone for medication-assisted treatment of opioid dependence (MATOD)

For a comparison of methadone and buprenorphine, see Comparison of buprenorphine and methadone in medication-assisted treatment of opioid dependence (MATOD).

For considerations before starting methadone, see Patient evaluation before starting MATOD and Legal and practical requirements before starting MATOD. Approval for each patient from the state or territory Department of Health is required before starting treatment with methadone. Contact with a specialist advisory service is encouraged.

Methadone is associated with QTc interval prolongation; it is important to perform an electrocardiogram (ECG) to assess QTc interval before starting methadone for patients with:

• known QTc prolongation
• potential symptoms of QTc prolongation (syncope, palpitations, dizziness)
• other risk factors, such as congenital long QTc syndrome (family history), cardiac abnormalities or use of other drugs that prolong the QTc interval.

Also perform an ECG periodically for patients taking more than 120 mg methadone dailyCentre for Alcohol and Other Drugs, 2018.

Methadone doses (initial and maintenance) should be individualised; titrate the dose to suppress withdrawal, minimise ongoing use of other opioids, maximise the patient’s function and avoid toxicity. Methadone has a long half-life (20 to 36 hours). During the start of treatment, methadone accumulates in the serum; serum concentrations may take 1 week to stabilise after each dose changeCentre for Alcohol and Other Drugs, 2018. Fatal toxicity can occur (even with doses as low as 30 mg daily) if the dose is increased too rapidly, or if the patient has low opioid tolerance or is using other sedatives (eg alcohol, benzodiazepines). Risk of overdose is particularly increased in the first 2 weeks of methadone treatment. ‘Start low, go slow, aim high’ is a helpful maxim. Review patients regularly when starting them on methadone to observe for any signs of opioid toxicity. Seek specialist advice before dosing if the patient is intoxicated or continues to use nonprescribed opioids. If a patient is intoxicated, methadone should not be given until the cause is determined. Naloxone or transfer to hospital may be indicated. For information on management of methadone overdose, see Management overview of opioid poisoning.

It may take several months to achieve a methadone dose at which a patient stops using nonprescribed opioids. Outcomes are usually better when higher maintenance doses are provided for longer periods; many patients are maintained in the range of 60 to 120 mg daily. Higher doses are sometimes required; seek specialist advice in these situations.

When starting methadone MATOD therapy for a patient who uses opioids daily and does not use other sedatives, a suitable regimen isCentre for Alcohol and Other Drugs, 2018: