nalmefene hydrochloride dihydrate at a glance
Medicine class
Opioid-system modulator used in alcohol dependence.
Treatment aim
Reduces alcohol consumption; it does not treat acute withdrawal or provide immediate detoxification.
Additional support
Used with continuing psychosocial support focused on adherence and reducing drinking.
Administration
Swallow the film-coated tablet whole; it may be taken with or without food.
Opioid warning
It can block opioid medicines, including some painkillers, cough remedies and opioid-dependence treatments.
What is nalmefene hydrochloride dihydrate used for?
The selected product is licensed for:
Reducing alcohol consumption in adults with alcohol dependence who remain at high drinking risk after initial assessment, have no physical withdrawal symptoms and do not require immediate detoxification.
Use with continuing psychosocial support aimed at treatment adherence and reduced alcohol consumption.
How does nalmefene hydrochloride dihydrate work?
Nalmefene acts at opioid receptors in the brain: it blocks mu and delta receptors and partially activates kappa receptors. By modifying reward-related pathways, it can reduce the drive to continue drinking. It does not stop alcohol causing intoxication.
nalmefene hydrochloride dihydrate preparations and strengths
Tablet
Route: Oral
Strengths: 18 mg
How to take nalmefene hydrochloride dihydrate
Take nalmefene exactly as prescribed. Swallow the tablet whole with water, with or without food.
Do not divide or crush the tablet: direct skin contact with nalmefene may cause sensitisation.
Nalmefene does not prevent impairment or intoxication from alcohol.
Dizziness, sleepiness, visual disturbance or reduced attention can affect driving or using machinery, especially when treatment begins.
nalmefene hydrochloride dihydrate side effects
Common or expected effects
- Nausea
- Dizziness
- Difficulty sleeping
- Headache
- Reduced appetite
- Drowsiness or reduced attention
- Vomiting, dry mouth or diarrhoea
- Sweating, muscle spasms or fatigue
Get urgent medical advice
- Swelling of the face, lips, tongue or throat, which may indicate angioedema
- Hallucinations, significant confusion or feeling detached from yourself, particularly if persistent or recurrent
- Prolonged painful erection
nalmefene hydrochloride dihydrate in pregnancy
Pregnancy data are limited and nalmefene is not recommended during pregnancy. Anyone who is pregnant, planning pregnancy or thinks they may be pregnant should discuss treatment with the prescriber rather than changing it without advice.
nalmefene hydrochloride dihydrate while breastfeeding
It is unknown whether nalmefene passes into human milk, and a risk to the infant cannot be excluded. The prescriber and parent should decide whether to stop breastfeeding or stop nalmefene after weighing the benefits of each.
nalmefene hydrochloride dihydrate interactions
Tell the prescriber and pharmacist about all prescribed, over-the-counter and recreational substances, especially opioids.
Opioid painkillers, such as morphine or oxycodone
Nalmefene may reduce or prevent pain relief; emergency opioid use can require specialist monitoring.
Methadone or buprenorphine
Concurrent use is contraindicated because nalmefene can block opioid effects and may precipitate withdrawal.
Opioid-containing cough, cold or antidiarrhoeal products
These products may not work adequately and should be checked with a pharmacist or prescriber.
Common questions about nalmefene hydrochloride dihydrate
Answers are fully visible for fast scanning and source review.
What is nalmefene hydrochloride dihydrate used for?
It is used with psychosocial support to help selected adults with alcohol dependence reduce alcohol consumption when they remain at high drinking risk and do not need immediate detoxification.
Does nalmefene hydrochloride dihydrate treat alcohol withdrawal?
No. It is not an acute withdrawal or detoxification treatment and is contraindicated after recent severe alcohol withdrawal.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.