About methadone hydrochloride
Opioid analgesic and opioid-dependence treatment
Used for
- Severe pain when other treatments are inadequate
- Treatment of opioid use disorder, as part of a supervised program
Usual adult dose
Pain: individualized, often 2.5–10 mg every 8–12 hours initially. Opioid use disorder: specialist-directed dosing and monitoring.
Usual dose in children
Pain: specialist-directed, weight-based dosing; not routinely used in children.
Common side effects
- Sleepiness, dizziness, nausea, constipation
- Sweating and dry mouth
- Slow or shallow breathing
- Dependence and withdrawal
Important warnings
- Overdose can be fatal, especially during treatment initiation or dose changes.
- Can cause dangerous heart-rhythm changes and breathing suppression.
- Avoid alcohol and sedatives unless specifically directed by a clinician.
- Do not stop suddenly; withdrawal may occur.
Pregnancy
Use only under medical supervision. Stopping during pregnancy can harm parent and fetus; treatment may be continued for opioid use disorder.
Breastfeeding
Methadone can pass into breast milk. Clinician guidance is important; monitor the infant for unusual sleepiness or breathing problems.
Interactions
- Alcohol, benzodiazepines, and other sedatives increase breathing suppression.
- Some medicines alter methadone levels, causing withdrawal or overdose.
- Medicines that prolong the QT interval may increase risk of abnormal heart rhythm.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.