HIV/hepatitis B and C:
Issues for the GP managing a patient on Opioid Substitution Treatment (OST) are:
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 buprenorphine/naloxone at the normal rate.
Where there is significant impairment it is suggested that the methadone serum level is checked every 2 to 3 months to ensure that it is not rising due to impaired metabolism of methadone. Seek the advice of BOPAS or a specialist gastroenterologist if there are concerns.
Methadone or buprenorphine/naloxone is a respiratory depressant and care should be taken in prescribing methadone or buprenorphine/naloxone to patients with these disorders.
Note that carbamazepine, phenytoin and phenobarbitone interact with methadone (see methadone or buprenorphine/naloxone interactions section).
Mental health disorders
Note that antidepressant and antipsychotic medications may interact with methadone or buprenorphine/naloxone (see methadone or buprenorphine/naloxone interactions).
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.