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Opioid Receptor Modulator (Alcohol Dependence — 'As-Needed' Therapy) Pregnancy: UK SPC §4.6: 'There are no or limited data (fewer than 300 pregnancy outcomes) from the use of nalmefene in pregnant women. Animal studies have shown reproductive toxicity. Selincro is not recommended during pregnancy.' Breast-feeding: animal data have shown excretion of nalmefene/metabolites in milk; it is unknown whether nalmefene is excreted in human milk and a risk to newborns/infants cannot be excluded — a decision must be made whether to discontinue breast-feeding or to discontinue/abstain from Selincro therapy. Fertility: in fertility studies in rats, no effects were observed on fertility, mating, pregnancy or sperm parameters.

Nalmefene

Brand names: Selincro

Nalmefene is an opioid receptor modulator licensed for the reduction of alcohol consumption in adults with alcohol dependence, taken as needed on days when drinking is anticipated rather than to maintain abstinence.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Reduction of alcohol consumption in adults with alcohol dependence, taken as-needed: one 18 mg film-coated tablet on each day the patient perceives a risk of drinking alcohol, preferably 1–2 hours prior to the anticipated time of drinking
Route: Oral — the film-coated tablet should be swallowed whole and should not be divided or crushed, because nalmefene may cause skin sensitisation when in direct contact with the skin. May be taken with or without food
Frequency: As-needed, on days the patient perceives a risk of drinking — not a fixed daily dose
Max: 18 mg (one tablet) per day — the SPC states 'The maximum dose of Selincro is one tablet per day'
INDICATION MATCH: this is the page's primary indication (alcohol dependence, 'as-needed' therapy), primary route (oral) and primary population (adults). The 18 mg strength is the strength of the product this SPC covers, 'Selincro 18mg film-coated tablets'; the §4.2 text expresses the dose as 'one tablet'. INITIATION: at an initial visit the patient's clinical status, alcohol dependence and level of alcohol consumption (based on patient reporting) should be evaluated; the patient should then record their alcohol consumption for approximately two weeks, and at the next visit Selincro may be initiated in patients who continued to have a high drinking risk level over that two-week period, in conjunction with psychosocial intervention focused on treatment adherence and reducing alcohol consumption. IF DRINKING HAS ALREADY STARTED: 'If the patient has started drinking alcohol without taking Selincro, the patient should take one tablet as soon as possible.' REVIEW: the greatest improvement was observed within the first 4 weeks in pivotal trials; response to treatment and the need for continued pharmacotherapy should be evaluated on a regular (for example, monthly) basis. Clinical data under randomised controlled conditions are available for 6 to 12 months, and 'Caution is advised if Selincro is prescribed for more than 1 year.' TREATMENT GOAL: 'Selincro is not for patients for whom the treatment goal is immediate abstinence.' SPECIAL POPULATIONS — no dose adjustment is recommended for the elderly (≥65 years), for mild or moderate renal impairment, or for mild or moderate hepatic impairment; caution is nevertheless advised in the elderly and in mild/moderate hepatic or renal impairment (for example, by more frequent monitoring), and in patients with elevated ALAT or ASAT (>3 times ULN), who were excluded from the clinical development programme. Severe hepatic impairment and severe renal impairment (eGFR <30 ml/min per 1.73 m²) are CONTRAINDICATIONS, not dose reductions. OPIOIDS: Selincro should be temporarily discontinued for 1 week prior to anticipated use of opioids, for example if opioid analgesics might be used during elective surgery; in an emergency the amount of opioid required to obtain the desired effect may be greater than usual and must always be titrated individually, with close monitoring for respiratory depression.

Paediatric dose

Route: Oral
NO PAEDIATRIC DOSE IS AVAILABLE FROM THIS SOURCE — dosePerKg is deliberately null and must not be derived from the adult dose. UK SPC §4.2, verbatim: 'The safety and efficacy of Selincro in children and adolescents <18 years of age have not been established. No data are available.'

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substance or to any of the excipients listed in section 6.1
  • Patients taking opioid agonists (such as opioid analgesics, opioids for substitution therapy with opioid agonists e.g. methadone, or partial agonists e.g. buprenorphine)
  • Patients with current or recent opioid addiction
  • Patients with acute symptoms of opioid withdrawal
  • Patients for whom recent use of opioids is suspected
  • Patients with severe hepatic impairment (Child-Pugh classification)
  • Patients with severe renal impairment (eGFR <30 ml/min per 1.73 m²)
  • Patients with a recent history of acute alcohol withdrawal syndrome (including hallucinations, seizures, and delirium tremens)

Side effects

  • Very common: nausea, dizziness, insomnia, headache — the majority mild or moderate, associated with treatment initiation and of short duration
  • Common: vomiting, dry mouth, diarrhoea; decreased appetite; sleep disorder, confusional state, restlessness, decreased libido; somnolence, tremor, disturbance in attention, paraesthesia, hypoaesthesia; tachycardia, palpitations; hyperhidrosis; muscle spasms; fatigue, asthenia, malaise, feeling abnormal; weight decreased
  • Uncommon: hallucination (auditory, tactile, visual and somatic), dissociation — mostly mild or moderate, associated with treatment initiation and lasting a few hours to a few days; these could represent alcoholic psychosis, alcohol withdrawal syndrome or comorbid psychiatric disease
  • Not known: visual impairment (mostly transient); angioedema, urticaria, pruritus, rash, erythema; myalgia; priapism
  • Precipitated opioid withdrawal — nalmefene is contraindicated in patients taking opioid agonists, with current or recent opioid addiction, or in whom recent opioid use is suspected

Monitoring

  • Record alcohol consumption for approximately two weeks before initiation, and confirm a continued high drinking risk level before starting
  • Regular (for example monthly) review of response, overall functioning, treatment adherence and potential side effects; caution if prescribed for more than 1 year
  • Psychiatric symptoms — if patients develop psychiatric symptoms that are not associated with treatment initiation and/or are not transient, consider alternative causes and reassess the need to continue. Selincro has not been investigated in unstable psychiatric disease, and the increased suicidal risk in alcohol and substance abusers is not reduced by nalmefene
  • Hepatic and renal function — more frequent monitoring in mild or moderate impairment; caution in patients with ALAT or ASAT >3 times ULN
  • Seizure history — limited experience in patients with a history of seizure disorders including alcohol withdrawal seizures; caution if treatment aimed at reduction of alcohol consumption is started in such patients
  • If opioids become necessary, record and communicate the time of last Selincro intake, and observe closely for respiratory depression
  • ⚠️ §4.4 in this source bundle is cut off at the source-fetch limit part-way through the UGT2B7 inhibitor paragraph, so this monitoring list is not exhaustive — consult the full SPC

Clinical monograph

How it works

It modulates the brain's reward system as an antagonist at mu and delta opioid receptors and a partial agonist at kappa receptors, reducing the reinforcing, rewarding effects of alcohol.

Prescribing in practice

  • It must not be used in patients taking opioids or who are opioid-dependent, as it can precipitate acute opioid withdrawal.
  • It is intended for those without physical withdrawal symptoms who do not require immediate detoxification, and should be combined with psychosocial support.
  • Caution is needed in hepatic or renal impairment and it should be avoided in severe impairment.

Monitoring

Monitor alcohol consumption, adherence and response at regular reviews, and assess continued clinical benefit periodically.

Counselling the patient

  • Take a dose on days when you anticipate a risk of drinking, ideally before or as soon as drinking is expected.
  • Tell any healthcare professional you take it before being given opioid painkillers.
  • It works alongside psychological support aimed at reducing how much you drink.

Evidence & guidelines

NICE technology appraisal supports nalmefene for reducing alcohol consumption in defined alcohol-dependent adults alongside continued psychosocial support.

Reference: NICE TA325 (nalmefene for alcohol dependence); Gual et al. Eur Neuropsychopharmacol 2013 (ESENSE1); Mann et al. Biol Psychiatry 2013 (ESENSE2); MHRA SPC Selincro; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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