naltrexone hydrochloride at a glance
Medicine class
Opioid-receptor antagonist
Licensed role
Supports abstinence and relapse prevention in alcohol dependence as part of comprehensive care
Key safety point
Opioids must be stopped and opioid freedom confirmed before treatment
Administration
Swallow the film-coated tablet with liquid
What is naltrexone hydrochloride used for?
Naltrexone is used with psychological support and a wider treatment plan.
Reducing alcohol craving, supporting abstinence and reducing relapse risk in alcohol dependence.
Supporting continued abstinence after opioid detoxification, once opioid freedom is clearly established.
How does naltrexone hydrochloride work?
Naltrexone competitively blocks opioid receptors. This prevents opioid effects and is thought to reduce the rewarding effects and craving associated with alcohol. It does not cause a disulfiram-like reaction with alcohol.
How to take naltrexone hydrochloride
Take exactly as prescribed and swallow with liquid. The selected scored tablet can be divided into equal halves if instructed. Do not start while using opioids or in opioid withdrawal, and tell healthcare professionals before surgery, anaesthesia or pain treatment.
Check painkillers, cough and cold remedies, and diarrhoea treatments with a pharmacist because some contain opioids.
Do not try to overcome the opioid blockade by taking large quantities of opioids.
Do not stop treatment without discussing it with the prescriber.
naltrexone hydrochloride side effects
Common or expected effects
- Nausea, vomiting or abdominal pain
- Headache, restlessness, nervousness or anxiety
- Difficulty sleeping
- Muscle or joint pain and weakness
- Dizziness
- Diarrhoea or constipation
- Rash
Get urgent medical advice
- Suicidal thoughts or attempted suicide
- Hepatitis or other liver problems, potentially with jaundice or marked illness
- Severe muscle injury, potentially causing intense muscle pain, weakness or dark urine
- Severe precipitated opioid withdrawal if taken while opioid-dependent
- Prolonged breathing or circulation problems if opioids are required or taken during the blockade
naltrexone hydrochloride in pregnancy
Naltrexone is not routinely recommended during pregnancy because safety evidence is limited. It may occasionally be considered when an experienced clinician judges that benefit outweighs risk. Do not make abrupt treatment changes without advice.
naltrexone hydrochloride while breastfeeding
The selected product information does not recommend breastfeeding during treatment. Specialist pharmacy guidance considers naltrexone usable with caution, but evidence is very limited and infant monitoring is advised.
naltrexone hydrochloride interactions
Give the prescriber and pharmacist a complete list of prescribed, non-prescribed and recreational substances.
Opioid painkillers, including codeine, tramadol and morphine
Naltrexone blocks their effects; attempts to overcome the blockade can cause fatal poisoning, and emergency analgesia requires specialist monitoring.
Opioid cough, cold or diarrhoea remedies
Their effects may be blocked and concurrent use is contraindicated.
Methadone and other opioid-substitution treatments
Naltrexone can trigger abrupt, potentially life-threatening withdrawal.
Common questions about naltrexone hydrochloride
Answers are fully visible for fast scanning and source review.
Why must I be opioid-free before starting naltrexone hydrochloride?
It can trigger severe, prolonged and potentially life-threatening withdrawal in an opioid-dependent person.
Does it make you sick if you drink alcohol?
No. It does not cause a disulfiram-type reaction with alcohol.
Can cough or cold medicines interact with it?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.