Drug reference
methadone
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Drug class
Musculoskeletal (Opioids)
Mechanism of action
Narcotic agonist-analgesic of opiate receptors; inhibits ascending pain pathways, thus altering perception and response to pain; produces analgesia, respiratory depression, and sedation
Common side effects
- Agitation
- Nausea
- Cardiac arrest
- Bradycardia
- Angina pectoris
- Syncope
- Urinary retension
Contraindications
- Hypersensitivity to methadone or formulation components; acute abdominal condition, toxin-mediated diarrhea, pseudomembranous colitis, respiratory depression; concurrent use of selegiline, hypercarbia, known or suspected gastrointestinal obstruction, including paralytic ileus, asthma (acute), signi…
- Acute pain or postoperative pain; pain that is mild or not expected to persist
Known interactions (5)
- clarithromycin + methadone Major
- fluconazole + methadone Major
- haloperidol + methadone Major
- itraconazole + methadone Major
- methadone + ondansetron Major
Related conditions
Frequently asked questions
What drug class is methadone?
methadone belongs to: Musculoskeletal.
How does methadone work?
Narcotic agonist-analgesic of opiate receptors; inhibits ascending pain pathways, thus altering perception and response to pain; produces analgesia, respiratory depression, and sedation
What are the common side effects of methadone?
Agitation, Nausea, Cardiac arrest, Bradycardia, Angina pectoris, Syncope, Urinary retension
Which drugs interact with methadone?
clarithromycin, fluconazole, haloperidol, itraconazole, ondansetron
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