Induction to methadone treatment
Size of the first dose
Stabilisation of methadone dose
Transfer from other pharmacotherapies
Missed doses and reintroduction of methadone
Cessation of methadone maintenance treatment
Induction to methadone treatment
Commencing methadone from heroin useDeaths due to methadone toxicity in the early stages of treatment have been related to:
- Concomitant use of other drugs, particularly sedatives;
- Inadequate assessment of tolerance;
- Commencement on doses that are too high for the level of tolerance;
- Inadequate understanding of the cumulative effect of methadone;
- Inadequate supervision of ingestion of methadone;
- Individual variation in metabolism of methadone.
Size of the first doseThe first dose of methadone should be determined for each patient based on the severity of dependence and level of tolerance to opioids.
- A dose of <20 mg for a 70kg patient can be presumed to be safe, even in opioid-na´ve users as this is the lowest dose at which toxicity has been observed.
- Caution should be exercised for starting doses of 30mg or more.
- Extreme care should be exercised when the initial dose of methadone exceeds 40mg.
Stabilisation of methadone doseStabilisation is about titrating the dose against needs of individual patients.
Monitoring during the first two weeks
- Patients should be observed daily prior to dosing and an assessment made of intoxication. If there are any concerns they should be seen by a doctor before the dose is administered.
- Because of the pharmacology of methadone, to ensure safety, it is desirable that patients are reviewed at least once, and preferably twice by an experienced clinician (doctor or nurse) in the first week with a view to assessing intoxication from methadone.
- Dose increases should only be considered subject to assessment by the prescriber.
- Do not increase the methadone dose for at least the first 3 days of treatment unless there are clear signs of withdrawal at the time of peak effect, ie 3-4 hours after dose.
- Consider dose increments of 5-10mg every 3 days subject to assessment.
- Total weekly increase should not exceed 20mg.
- The maximum dose at the end of the first week should typically be no more than 40mg.
Transfer from other pharmacotherapiesSeek specialist advice when prescribing for patients who are transferring from other pharmacotherapies.
Buprenorphine(See also "National guidelines and procedures for the use of buprenorphine in the treatment of heroin dependence")
- Stabilise on daily doses of buprenorphine and reduce dose to 16mg or less for several days prior to transfer.
- Commence methadone 24 hours after the last dose of buprenorphine.
- The initial methadone dose should not exceed 30mg.
- For transfer from doses of 4 mg or less, commence on lower doses of methadone.
- Do not increase the dose of methadone in the first three days.
- Treat patients transferring from naltrexone as if they were na´ve to opioids and non tolerant to their effects unless the assessment clearly indicates a return to regular, heavy heroin use.
- Do not administer methadone until at least 72 hours after the last dose of naltrexone.
- Extreme caution should be exercised with commencing doses of methadone greater than 20mg.
Dose levelsDoses should be determined for individual patients. Doses for effective MMT are typically 60-100mg per day.
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Changing dose levelThe following must be taken into consideration when considering dose changes:
- Concurrent use of illicit opioids and continued injecting use
- Individual variation in methadone metabolism
- Use of other medications
- Polydrug use
Monitoring drug useUrine Testing:
- Urinalysis is most useful in the following circumstances:
- Patients in the early stages of treatment.
- Where clarity of drug use is required for diagnostic purposes.
- Medicare allows for a maximum of 21 urinalysis tests per patient per year.
Adjunct treatmentProviding therapies such as motivational interviewing, relapse prevention, counselling, social skills training, vocational, financial, accommodation and family assistance contributes positively to the progress of MMT. However, participation in these should be voluntary.
- The takeaway policy for methadone is determined for each jurisdiction in line with the National Policy on Methadone Treatment. There are both benefits and problems associated with takeaway doses and particular care should be exercised when authorising this as a component of management.
- Takeaway doses for interstate or overseas travel must be organised through the jurisdictional authority responsible for controlling methadone and the Australian Government Department of Health and Ageing.
Missed doses and reintroduction of methadoneIn general the following schedule can be presumed to be safe and effective. If the patient has missed:
- One day: No change in dose.
- Two days: If no evidence of intoxication administer normal dose.
- Three days: Administer half dose in discussion with the prescriber.
- Four days: Patient must see prescriber. Recommence at 40mg or half dose whichever is the lower.
- Five days or more: Regard as a new induction.
Cessation of methadone maintenance treatmentIt is recommended that patients be encouraged to remain in treatment for at least 12 months to achieve enduring lifestyle changes.
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Voluntary withdrawal schedule
- The recommended rate of reduction is10mg/week to 40mg/day, then 5mg/week. Rates of reduction should be negotiated with patients, and dose changes should occur once a week.
- Abrupt cessation of methadone could be considered from 40mg/day with administration of clonidine and symptomatic medications as needed.
- Supportive care/after care:
- Supportive care should be offered for at least 6 months following cessation of methadone.
- For recently discharged patients fast readmission to MMT should be available.
- It is sometimes necessary to discharge a patient from treatment for the safety or well being of the patient, other patients or staff.
- Patients should, where possible, be withdrawn to 40mg/day according to the above voluntary withdrawal schedule.
- Abrupt cessation of methadone or rapid dose reduction may occasionally be warranted in cases of violence, assault or threatened assault against staff or patients.
Transfer to naltrexone
- Administration of naltrexone to a patient physically dependent on opioids will precipitate a severe withdrawal syndrome.
- Patients being transferred to naltrexone should undergo detoxification followed by a 14 day drug free period to allow stored methadone to be eliminated from the body.
- Seek specialist advice from an alcohol and drug service if it is not possible to follow this regime.
Transfer to buprenorphineSee the National Buprenorphine Guidelines for further information or seek specialist advice.
- When methadone patients take a dose of buprenorphine, it may precipitate withdrawal.
- Patients on low doses of methadone (<30mg) generally tolerate this transfer with minimal discomfort.
- Very low doses of buprenorphine (eg 2 mg) are generally not adequate to substitute for methadone while high doses (8 mg or more) are more likely to precipitate withdrawal.
- Buprenorphine should not be dispensed within 24 hours of last methadone dose. Increasing the interval between the last dose of methadone and the first dose of buprenorphine reduces the incidence and severity of precipitated withdrawal.