Treatment: opioid substitution treatment (buprenorphine, methadone)

Laboratory tests

• HIV serology
• Hepatitis C serology
• Hepatitis B serology
• AST
• ALT
• GGT
• FBC
• hCG (woman of childbearing potential)if neededWoman of childbearing potential: a pregnancy test is requested before treatment by the Quebec guidelines ^[2] and, depending on the history, by the Swiss recommendations ^[3]; the French texts cited (2004 consensus conference, 2022 HAS page) do not include it in the tests ^[4,5].
• Syphilis serology (if at-risk sexual behaviour)if needednon-French guidelineSexual risk behaviour: in the United States, the ASAM (2020) asks that STI screening be strongly considered in the initial assessment of opioid use disorder ^[6], and the Swiss recommendations provide for it depending on the history ^[3]; the French texts cited on opioid substitution treatment (2004 consensus conference, 2022 HAS page) do not mention it ^[4,5]. See the page “Sexually transmitted infections (STIs)”.
• Chlamydia trachomatis and Neisseria gonorrhoeae NAAT (PCR) (if at-risk sexual behaviour)if needednon-French guidelineSexual risk behaviour: STI screening to be strongly considered according to the ASAM (United States, 2020) ^[6], depending on the history in the Swiss recommendations ^[3]; the French texts cited on opioid substitution treatment (2004 consensus conference, 2022 HAS page) do not mention it ^[4,5]. Sampling sites according to practices and exposure: see the page “Sexually transmitted infections (STIs)”.

± if methadone and risk factor for QT prolongation

• Serum potassiumif neededPatient on methadone with a risk factor for QT prolongation: history of QT prolongation, family history of sudden death, dose above 120 mg/day, advanced heart disease, drug that lowers potassium, slows the heart rate or causes torsades de pointes.
• Serum magnesiumif neededPatient on methadone with a risk factor for QT prolongation: history of QT prolongation, family history of sudden death, dose above 120 mg/day, advanced heart disease, drug that lowers potassium, slows the heart rate or causes torsades de pointes.
• ECG (not a laboratory test): see the note for the divergent positions on the indication and frequency

Urine tests

• Urine drug screen (looking for methadone or buprenorphine depending on the treatment)