Nalmefene
Pronunciation: (nal-MEH-feen).
- Generic name
- Nalmefene
- Brand names
- Selincro, Nalmefene, Nalfen, Nalmef
- Drug class
- Opioid receptor modulator (opioid antagonist)
Availability and supply rules vary by country
Trade names by country: United States
Australia: · Full directory
What Nalmefene is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Nalmefene works
Nalmefene is an opioid receptor modulator that acts as an antagonist at the mu and delta opioid receptors and a partial agonist at the kappa receptor. By blocking these receptors, nalmefene reduces the reinforcing and rewarding effects of alcohol, thereby decreasing alcohol consumption. (1)
What Nalmefene is used for
Reduction of alcohol consumption in adults with alcohol use disorder and a high drinking-risk level (this oral 18 mg tablet is EU-approved only — see regulatory-status warning)
"High drinking-risk level" is defined as more than 60 g pure alcohol/day for men or more than 40 g pure alcohol/day for women, without physical withdrawal symptoms and not requiring immediate detoxification. Recovered from the clinician database description (a data-recovery fix — the automated extractor had left this field empty even though the description text names it). (2)
Before taking Nalmefene
Do not take / not appropriate for
- hypersensitivity to nalmefene, severe hepatic or renal impairment, and current opioid use (due to risk of withdrawal). (Contraindication) (2)
Tell your clinician about
(2)How to take Nalmefene
- General Instructions: Take nalmefene exactly as prescribed by your healthcare provider. It is usually taken orally, with or without food.. Adult Dosing: The recommended dose is one 18 mg tablet as needed, preferably 1–2 hours before a possible drinking situation. Do not take more than one tablet per day.. Pediatric Dosing: Nalmefene is not recommended for use in children or adolescents under 18 years of age.. Administration: Swallow the tablet whole with water. Do not crush or chew the tablet.. When To Stop: Continue taking nalmefene as directed until your healthcare provider advises you to stop. Do not discontinue abruptly without consulting your doctor.. Storage: Store at room temperature, away from moisture and heat. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (2)
Missed dose
If you miss a dose and are at risk of drinking, take the missed dose as soon as you remember. Do not take more than one dose per day. If you are not at risk of drinking, skip the missed dose.
Overdose
In case of overdose, seek emergency medical attention immediately. Symptoms may include confusion, agitation, hallucinations, or seizures. Supportive care and monitoring are recommended. (2)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Dizziness or sleepiness
Incidence: Recovered from the clinician-authored database warnings text (a data-recovery fix); frequency not established
Precipitated opioid withdrawal symptoms in people dependent on opioids
Incidence: Recovered from the clinician-authored database warnings text (a data-recovery fix); frequency not established
Serious warnings
REGULATORY STATUS (ADDED — the earlier draft of this record made no US/EU distinction) — serious
Symptoms: REGULATORY STATUS (ADDED — the earlier draft of this record made no US/EU distinction): this 18 mg oral, as-needed nalmefene tablet (Selincro) is approved by the EMA for alcohol-consumption reduction in the EU (since 2013) but is NOT FDA-approved and is not available in the United States. A different nalmefene product — Opvee, a nasal spray — was FDA-approved in 2023 for a completely different purpose (reversing acute opioid overdose) at a different dose and route; it is not interchangeable with, and should not be confused with, this oral alcohol-reduction tablet.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Nalmefene can precipitate withdrawal symptoms in people dependent on opioids — serious
Symptoms: Nalmefene can precipitate withdrawal symptoms in people dependent on opioids. Use caution in patients with a history of seizures. Monitor for signs of liver dysfunction. May cause dizziness or sleepiness.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Contraindications recorded in the clinician database — serious
Symptoms: Contraindications recorded in the clinician database: Contraindications include hypersensitivity to nalmefene, severe hepatic or renal impairment, and current opioid use (due to risk of withdrawal). Use with caution in patients with a history of seizures, psychiatric disorders, or moderate hepatic/renal impairment (no dose adjustment needed for mild/moderate hepatic impairment or mild/moderate renal impairment, but more frequent monitoring is advised). Monitor for suicidal ideation and liver function abnormalities.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Nalmefene may interact with opioid-containing medications, increasing the risk of withdrawal symptoms. Inform your healthcare provider about all medicines you are taking, including over-the-counter drugs and supplements. Use caution with medications that affect liver enzymes. | (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
Animal studies have shown reproductive toxicity. Nalmefene is not recommended during pregnancy, and a risk to the newborn/infant cannot be excluded — discuss with the clinician managing the pregnancy. (2)
Breastfeeding
It is not known whether nalmefene passes into human breast milk; animal studies show nalmefene and its metabolites do pass into breast milk. Nalmefene is not recommended during breastfeeding because the potential risk to the infant cannot be ruled out. (2)
Children
Frequency: Not applicable.. Weight Based: Not recommended for pediatric use.. Max Daily Dose: Not applicable.. Max Single Dose: Not applicable.. Age Restrictions: Safety not established in children. (2)
Renal_impairment
Contraindicated in severe hepatic or renal impairment. No dose adjustment is needed in mild or moderate hepatic impairment or mild or moderate renal impairment, but more frequent monitoring is advised in these patients. (2)
Hepatic_impairment
Contraindicated in severe hepatic or renal impairment. No dose adjustment is needed in mild or moderate hepatic impairment or mild or moderate renal impairment, but more frequent monitoring is advised in these patients. (2)
Monitoring
(2)Storage
This product does not require any special storage conditions. Shelf life is 3 years. Keep out of reach of children.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
EU only (not FDA-approved / not available in the US — see regulatory-status warning)
Indication: Alcohol consumption reduction
Dose summary: The recommended dose of nalmefene is 18 mg administered as a single oral dose, as needed, on each day a drinking risk is perceived, preferably 1-2 hours before the anticipated drinking. Maximum one tablet per day.
Renal context: Contraindicated in severe renal impairment; no dose adjustment needed in mild/moderate renal impairment, with more frequent monitoring advised. (1) (2)
Frequently asked questions
What is nalmefene used for?
Nalmefene is used to help reduce alcohol consumption in adults with alcohol dependence who have a high drinking risk level. It is not a cure for alcoholism but can support efforts to reduce drinking.
How does nalmefene work?
Nalmefene works by blocking opioid receptors in the brain, which reduces the rewarding effects of alcohol and helps decrease the urge to drink.
Can I take nalmefene every day?
Nalmefene is intended to be taken only on days when you anticipate a risk of drinking, not every day. Follow your healthcare provider’s instructions.
Is nalmefene safe with other medications?
Nalmefene should not be used with opioid-containing medications. Always inform your healthcare provider about all medicines you are taking to avoid interactions.
What should I do if I experience side effects?
Mild side effects often improve with time. If you experience severe or persistent symptoms, contact your healthcare provider immediately.
Can nalmefene be used in pregnancy or breastfeeding?
Nalmefene is not recommended during pregnancy or breastfeeding unless the potential benefit outweighs the risk. Discuss with your doctor.
Is nalmefene available in Australia?
Per the clinician database, nalmefene (Selincro) is listed on the Australian Register of Therapeutic Goods. This oral 18 mg alcohol-reduction tablet is also approved in the EU, but is NOT FDA-approved and is not available in the United States — a different nalmefene product (a nasal spray for opioid-overdose reversal) is FDA-approved for an unrelated use.
What happens if I take too much Nalmefene?
Taking too much Nalmefene can lead to an exacerbation of side effects such as nausea, vomiting, and dizziness. While it is an opioid antagonist, an overdose can still be serious. If you suspect an overdose, seek immediate emergency medical attention. Do not attempt to self-treat and inform medical professionals about the amount taken.
Can I drink alcohol while taking Nalmefene?
It is generally not recommended to drink alcohol while taking Nalmefene. As an opioid antagonist, Nalmefene can interact with substances that affect the central nervous system, including alcohol. This combination may increase the risk of side effects like dizziness, drowsiness, and impaired coordination. Always consult your healthcare provider for personalized advice regarding alcohol consumption with Nalmefene.
Is Nalmefene safe during pregnancy?
Nalmefene is categorized as 'Consult doctor' for pregnancy, meaning its safety during pregnancy has not been definitively established. The potential risks and benefits to both the mother and the fetus must be carefully weighed. If you are pregnant, planning to become pregnant, or breastfeeding, it is crucial to discuss the use of Nalmefene with your healthcare provider to determine the most appropriate course of action.
What is the mechanism of action of Nalmefene?
Nalmefene is an opioid receptor modulator that acts as an antagonist at the mu and delta opioid receptors and a partial agonist at the kappa receptor. By blocking these receptors, nalmefene reduces the reinforcing and rewarding effects of alcohol, thereby decreasing alcohol consumption. (1)
What is the generic name of Nalmefene?
The generic name is Nalmefene. It is sold under brand names including Selincro, Nalmefene, Nalfen, Nalmef.
What class of drug is Nalmefene?
Nalmefene is classed as: Opioid receptor modulator (opioid antagonist).
References
- Nalmefene clinician-authored medicine recordMedGuideGlobal · Not specified · accessed 2026-08-06 · source 1
- Selincro 18 mg film-coated tablets - Summary of Product Characteristicselectronic Medicines Compendium (UK) and European Medicines Agency · European Union / United Kingdom · accessed 2026-08-06 · source 2
- ZURNAI (NALMEFENE HYDROCHLORIDE) INJECTION, SOLUTION [KNOA PHARMA LLC ] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- nalmefene hydrochloride — FDA approval record (Drugs@FDA ANDA216007)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 4
- Nalmefene — RxNorm normalized drug concept (RXCUI 236069)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 5
Brand names by country
Single-ingredient Nalmefene names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Zurnai1.5 mg/.5mL · knoa pharma llc
- OPVEE2.7 mg00uL · indivior inc.