When patients miss methadone doses they may use other drugs including other central nervous system depressants such as alcohol or benzodiazepines. When methadone doses are missed for 3 or more days, tolerance to opioids may be reduced placing patients at increased risk of overdose when methadone is reintroduced.


  • Patients should be assessed for signs of intoxication and withdrawal before dosing is recommenced after missed doses (also see Section 4.3, Appendix 2 and Appendix 3).

  • If the dose has not been collected for 3 or more consecutive days the dose should be withheld or reduced until the patient has been assessed by the prescriber.

  • In 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.