Clinical guidelines and procedures for the use of methadone in the maintenance treatment of opioid dependence

2.1 Entry into methadone maintenance treatment

Page last updated: August 2003

Note: Jurisdictional requirements stipulating eligibility for entry to MMT may vary from state to state and from time to time. These guidelines are an attempt to present the clinical basis for MMT. If in doubt consult your jurisdictional policy.

Indications
Contraindications
Precautions

Indications

Methadone maintenance treatment is indicated for those who are dependent on opioids and who have had an extended period of regular opioid use.

The diagnosis of opioid dependence should be made by eliciting the features of opioid dependence in a clinical interview (See Section 2.2 Assessment for treatment with methadone). The definitional criteria of The diagnostic and statistical manual of mental disorders, 4th edition (DSM-IV) are useful to diagnose dependence.

Diagnostic Definition of Opioid Dependence (DSM IV)

Dependence is defined as "A maladaptive pattern of substance use leading to clinically significant impairment or distress as manifested by three or more of the following occurring at any time in the same 12 month period."
  • Tolerance as defined by either of the following:

    • A need for markedly increased amounts of opioids to achieve intoxication or desired effect;
    • Markedly diminished effect with continued use of the same amount of opioids.

  • Withdrawal as manifested by either of the following:

    • The characteristic withdrawal syndrome for opioids (see section 1.1).
    • Opioids or a closely related substance are taken to relieve or avoid withdrawal symptoms.

  • Opioids are often taken in larger amounts or over a longer period than was intended. Top of page

  • There is a persistent desire or unsuccessful attempts to cut down or control opioid use.

  • A great deal of time is spent in activities necessary to obtain opioids, use opioids, or recover from their effects.

  • Important social, occupational, or recreational activities are given up or reduced because of opioid use.

  • The opioid use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by opioids.

    NOTE: A person diagnosed as opioid dependent may or may not be physically dependent on opioids at the time of presentation. If there is no current physical dependence MMT will not usually be appropriate. For those not physically dependent at the time of presentation, the prescribing practitioner must clearly document that the potential benefits to the individual's health and social functioning outweigh the disadvantages of MMT.

  • The patient will usually be at least 18 years of age. The prescribing doctor should seek a second or specialist opinion before treating anyone under 18 years of age. However, methadone treatment should not be precluded on the grounds of age alone.

  • The patient must be able to provide proof of identity – a requirement for treatment with any S8 medication.

  • The patient must be able to give informed consent to treatment with methadone.

Suitability for methadone treatment

  • opioid dependent

  • 18 years or older

  • proof of identity

  • capable of informed consent

Contraindications

The following categories of patients are not suitable for treatment with methadone:
  • Patients with severe hepatic impairment (decompensated liver disease) as methadone may precipitate hepatic encephalopathy.

  • Generally treatment other than methadone should be considered for a person under the age of 18 years, however, methadone treatment should not be precluded solely on the grounds of age. The prescribing doctor should check jurisdictional requirements regarding age limits for MMT.

  • Where patients are unable to give informed consent due to presence of a major psychiatric illness or being underage, the prescribing doctor should consider relevant secondary consultation and check jurisdictional requirements regarding obtaining legal consent.

  • Patients who are hypersensitive to methadone or other ingredients in the formulation.

  • Other contraindications identified by the manufacturers of methadone include severe respiratory depression, acute asthma, acute alcoholism, head injury and raised intracranial pressure, ulcerative colitis, biliary and renal tract spasm, and patients receiving monoamine oxidase inhibitors or within 14 days of stopping such treatment. It is recommended that specialist advice be sought in these cases.
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Precautions

Particular caution should be exercised by prescribers when assessing individuals with the following clinical conditions as to their suitability and safety for treatment with methadone. Concomitant medical and psychiatric problems and other drug use increase the complexity of management of patients on MMT and may also increase the risk of overdose and death. The prescribing doctor should seek specialist advice or assistance in such cases.
  • High risk poly drug use: all opioid substitution treatments should be approached with caution in individuals using other drugs, particularly those likely to cause sedation such as alcohol, as well as benzodiazepines and antidepressants in doses outside the normal therapeutic range. Particular attention should be given to assessing the level of physical dependence on opioids, co-dependence on other drugs and overdose risk. (see Section 4.2 and Section 4.9).

  • Co-occurring alcohol dependence: due to the significant management problems presented by this group, consideration should be given to concurrent disulfiram or acamprosate therapy. If disulfiram or acamprosate are used, a methadone liquid formulation that does not contain alcohol should be considered to reduce the risk of reactions.

  • Recent history of reduced opioid tolerance: after a period of treatment with naltrexone, or having recently completed a period in prison or an opioid withdrawal program, the patient can be expected to have reduced tolerance to opioids and is at significant risk of overdose if they use opioids (see Section 3.1).

  • Psychiatric illness (also see Section 4.12):

    • People whose mental state impairs their capacity to provide informed consent : (e.g. those with an acute psychotic illness, cognitive impairment or a severe adjustment disorder) should receive adequate treatment for the psychiatric condition so that informed consent can be obtained before initiation of MMT. (Note: at entry to methadone most patients exhibit some degree of depression which usually resolves quickly with MMT. Most of these patients do not require antidepressant treatment before commencement of methadone).

    • High risk of self-harm: Individuals at moderate or high risk of suicide should not be commenced on methadone in an unsupervised environment and specialist consultation should be sought.

  • Chronic pain – refer for specialist assessment first

  • Concomitant medical problems:

    A significant proportion of methadone related deaths involve individuals who were in poor health and had other diseases (particularly hepatitis, HIV and other infections) which may have contributed to their death. This emphasises the importance of giving consideration to concomitant medical problems.

    • Head injury and increased intracranial pressure: This is generally seen only in the hospital emergency setting.

    • Phaeochromocytoma: aggravated hypertension has been reported in association with heroin use.

    • Asthma and other respiratory conditions: In such patients even usual therapeutic doses of opioids may decrease the respiratory drive associated with increased airways resistance.

    • Special risk patients: Methadone should be used with caution in the presence of hypothyroidism, adrenocortical insufficiency, hypopituitarism, prostatic hypertrophy, urethral stricture, shock and diabetes mellitus.

    • Poor compliance: patients who exhibit poor compliance with treatment for major intercurrent illness such as asthma or diabetes pose a particular challenge in MMT.
Top of pageExercise caution with patients in any of the following categories:
  • high risk polydrug use

  • co-occurring alcohol dependence

  • history of reduction in opioid tolerance

  • psychiatric illness

  • concomitant medical problems