methadone hydrochloride: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
methadone hydrochloride: clinical details
Prescribing considerations
- For opioid dependence, prescribe within a structured programme with regular review and coordinated dispensing.
- Avoid abrupt cessation because physical dependence and withdrawal are expected.
- Assess respiratory, cardiac, hepatic and renal risk and review interacting substances and medicines.
- For pain, use specialist expertise because conversion from other opioids is complex and accumulation can be delayed.
Contraindications and cautions
- Hypersensitivity to methadone or formulation excipients.
- Respiratory depression, obstructive airways disease or an acute asthma attack.
- Concurrent monoamine oxidase inhibitor treatment or use within the product-specified washout period.
- Risk of paralytic ileus.
- Selected products have additional contraindications; verify the specific SmPC.
Monitoring
- Monitor sedation, respiratory function, intoxication, withdrawal, adherence and diversion.
- Assess QT risk factors, interacting medicines and electrolytes; obtain ECG monitoring where product information recommends it.
- Review hepatic and renal function where clinically relevant.
Clinical pharmacology
Methadone is predominantly a mu-opioid receptor agonist. Its long, highly variable elimination and slow release from tissues can cause accumulation and delayed respiratory toxicity.
Formulation and product differences
- Selected products include ready-to-use oral solutions, sugar-free oral solutions, an oral concentrate requiring dilution and solution for subcutaneous or intramuscular injection.
- Oral products differ in excipients; check suitability for allergies, intolerances and hepatic or renal impairment.
- Licensed indications and age restrictions differ across products; consult the exact product SmPC.
methadone hydrochloride preparations and strengths
Oral mixture
Route: Oral
Strengths: 1 mg/mL
Oral solution
Route: Oral
Strengths: 1 mg/1 mL, 1 mg/mL
Tablet
Route: Oral
Strengths: 5 mg
methadone hydrochloride interactions
Methadone has important interactions. Check all prescribed, non-prescribed and herbal products with a pharmacist or prescriber.
Alcohol
Adds to sedation, low blood pressure and breathing suppression; avoidance is advised.
Benzodiazepines, sleeping medicines and other sedatives
Can cause profound sedation, respiratory depression, coma or death.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.