About naltrexone
Opioid receptor antagonist
Used for
- Treats alcohol use disorder
- Treats opioid use disorder alongside counseling and support
- Low-dose use for other conditions is off-label, with limited evidence
Usual adult dose
Standard treatment: alcohol use, 50 mg once daily; opioid use, usually 50 mg daily after withdrawal. Low-dose regimens vary and are not established.
Common side effects
- Nausea or vomiting
- Headache or dizziness
- Sleep problems or anxiety
- Liver enzyme changes
Important warnings
- Can trigger severe withdrawal if opioids remain in the body
- Blocks opioid pain medicines and may complicate emergency pain treatment
- Liver injury is possible; seek urgent care for jaundice or dark urine
- Do not stop or change opioid treatment without clinical supervision
Pregnancy
Human pregnancy data are limited; use requires a clinician’s assessment of benefits and risks.
Breastfeeding
Information is limited; discuss use with a clinician, especially when treating opioid use disorder.
Interactions
- Opioid pain medicines, cough medicines, or opioid-containing medicines
- Opioid-dependence treatments such as methadone or buprenorphine
- Other medicines that can affect the liver
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 It may be incomplete or out of date.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.