Mental Health  |  OST Pathway - Concurrent Medical Conditions

Mental Health

OST Pathway - Concurrent Medical Conditions

HIV/hepatitis B and C:

Issues for the GP managing a patient on Opioid Substitution Treatment (OST) are:

  • Testing for HIV, Hepatitis A, B and C (including Hep C PCR RNA test).
  • Preventing infection/transmission.
  • Monitoring LFTs in those with chronic Hepatitis B & C.
  • Referral for specialist assessment and treatment. Note: The Hepatitis Foundation service will consider treating previous intravenous drug users with interferon and ribavirin when they are stable on OST and no longer injecting. This can be a motivating factor for patients to stop IV use.
  • Offering Hepatitis A & B vaccination to those who are HAV & HBV antibody negative.

Chronic liver disease:

Patients with chronic liver disease on long-term opioid maintenance usually do not require alterations in their dose. However, if there is an abrupt change in liver function they may require dose adjustment. The development of jaundice is also a sign that the liver may not be able to metabolize methadone or suboxone at the normal rate.

Where there is significant impairment it is suggested that the methadone or suboxone serum level is checked every 2 to 3 months to ensure that it is not rising due to impaired metabolism of methadone or suboxone. Seek the advice of BOPAS or a specialist gastroenterologist if there are concerns.

Respiratory disorders

Methadone or suboxone is a respiratory depressant and care should be taken in prescribing methadone or suboxone to patients with these disorders.


Note that carbamazepine, phenytoin and phenobarbitone interact with methadone (see methadone or suboxone interactions section).

Mental health disorders

Note that antidepressant and antipsychotic medications may interact with methadone or suboxone (see methadone or suboxone interactions).

Last updated : Friday, August 21, 2015
Next review date : Saturday, August 20,2016

Disclaimer: This site is intended to be flexible and frequently updated. While every effort has been made to ensure accuracy, all information should be verified.