Nalmefene 18mg tablets
Requires a prescription from a doctor or prescriber
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Safety monitoring data
Yellow Card reports
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Data from the MHRA Yellow Card scheme. A reported reaction does not necessarily mean the medicine caused it. Contains public sector information licensed under the Open Government Licence v3.0.
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Suspected adverse reactions reported for Nalmefene
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1 branded products available
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Selincro 18mg tablets
This is the NHS Drug Tariff indicative price used for reimbursement purposes. It may not reflect the price paid by patients or pharmacies.
View full Drug TariffSource: NHS Drug Tariff via NHSBSA. Derived from dm+d VMPP (Virtual Medicinal Product Pack) pricing data. Contains public sector information licensed under the Open Government Licence v3.0.
WHO defined daily dose (DDD)
18 mg
Not a recommended dose. The DDD is the assumed average maintenance dose per day for a drug used for its main indication in adults. It is a statistical measure used for research and comparison purposes only.
Source: WHO Collaborating Centre for Drug Statistics Methodology, distributed via the NHS dm+d supplementary mapping files (NHSBSA). Contains public sector information licensed under the Open Government Licence v3.0.
Therapeutically similar medicines
Similarity is based on WHO Anatomical Therapeutic Chemical (ATC) classification and on a factual NHS dm+d therapeutic-grouping code prefix. Source data: NHS dm+d via TRUD (OGL v3.0), WHO ATC/DDD Index.
NHS prescribing volume and spending trends
Guidelines from the National Institute for Health and Care Excellence
NICE clinical guidance(3)
Nalmefene for reducing alcohol consumption in people with alcohol dependence (TA325)
Alcohol-use disorders: diagnosis, assessment and management of harmful drinking (high-risk drinking) and alcohol dependence (CG115)
Gambling-related harms: identification, assessment and management (NG248)
Source: National Institute for Health and Care Excellence (NICE). Contains public sector information licensed under the Open Government Licence v3.0.
Check stock at pharmacies and supply information
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Supply & safety information
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Pharmacy links redirect to the retailer's own search and do not represent real-time stock levels. Shortage and safety information sourced from MHRA drug safety updates (gov.uk, Crown Copyright under OGL v3.0).
Codes for healthcare professionals and prescribing systems
These codes are used by healthcare IT systems and prescribers to identify this medicine.
NHS UK identifiers
Browse tools
SNOMED CT and dm+d codes from NHS TRUD (Technology Reference data Update Distribution), licensed under the Open Government Licence v3.0. ATC codes from the WHO Collaborating Centre for Drug Statistics Methodology (whocc.no).
Active and completed clinical studies from ClinicalTrials.gov
Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine (NLM), National Institutes of Health (NIH). Data accessed via ClinicalTrials.gov API v2. Trial information is provided for research purposes and does not constitute medical advice.
Academic studies and reviews for this medicine's active substance
Showing the 50 most relevant studies.
Reviews & meta-analyses: 21 · Randomised trials: 15 · 1986–2026
Showing the 50 most relevant studies, sorted by most relevant.
He J, Luo W, Mei Y, et al.
2023
- Pulmonary Disease, Chronic Obstructive
- Respiratory Insufficiency
- Noninvasive Ventilation
Higginbotham B, Perez JK, Louie E, et al.
2024
- Alcoholism
- Ethanol
- Naltrexone
ObjectiveAlcohol use disorders confer a significant burden of disease and economic cost worldwide. However, the utilisation of pharmacotherapies to manage alcohol use disorder is poor. We aimed to conduct a systematic review of economic evaluation studies of alcohol use disorder pharmacotherapies.MethodsA search was conducted in Embase, Medline, CINAHL, PsychINFO and EconLit (August 2019, updated September 2022). Full economic evaluations using pharmacotherapy to treat alcohol use disorders were included. Included studies were stratified by medication and summarised descriptively. The Consensus on Health Economic Criteria list was used to assess the methodological quality.ResultsA total of 1139 studies were retrieved, of which 15 met the inclusion criteria. All studies were conducted in high-income countries. Four studies analysed nalmefene, four studies assessed acamprosate, three for naltrexone and four for stand-alone and/or combinations of naltrexone and acamprosate. There were 21 interventions synthesised from 15 studies as some studies evaluated multiple interventions and comparators. More than half of the included studies (73%) reported pharmacotherapy as dominant (less costly and more effective than comparators). From healthcare payer perspectives, five studies found that pharmacotherapy added to psychosocial support was dominant or cost-effective, accruing additional benefits at a higher cost but under accepted willingness to pay thresholds. Three analyses from a societal perspective found pharmacotherapy added to psychosocial support was a dominant or cost-effective strategy. Quality scores ranged from 63% to 95%.ConclusionPharmacotherapy added to psychosocial support was cost-effective from both healthcare and societal perspectives, emphasising an increased role for pharmacotherapy to reduce the burden of alcohol use disorders.
Abstract licence: CC BY
Zhanqi Zhao, Junting Zhang, Zhongqun Wang, et al.
Journal of Thoracic Disease, 2024
Rolland B, Karila L, Franchitto N, et al.
2025
- Alcoholism
- Baclofen
- Drug Approval
Ever since 2018 France has been the only country to approve the gamma aminobutyric acid type B (GABA-B) receptor agonist baclofen for alcohol dependence. This authorization follows a ten-year period of intensive off-label use during which baclofen was used in doses of up to 300 and even 400mg per day to support the gradual reduction of alcohol consumption in patients suffering from alcohol dependence. However, in international clinical trials, baclofen has mainly been studied to support the maintenance of abstinence. The French use of baclofen was therefore somewhat atypical as it paved the way for drug-supported approaches to reducing alcohol consumption, even before nalmefene was marketed. In line with this specific use of baclofen, approval was granted only for alcohol reduction support. However, a recent Cochrane systematic review and meta-analysis by Agabio et al. found significant efficacy only for abstinence maintenance, while no significant effect was found on alcohol reduction outcomes and no dose-response relationship was identified in the analyses. The safety of baclofen was judged to be good. Based on these substantial new results, the Société française d'alcoologie (SFA) now considers that baclofen should also be approved for the maintenance of abstinence. The extension of approval should not lead to the removal of the initial indication or the possibility of using high doses, as some patients have found this therapeutic regimen particularly useful for them. France, which has been a open skies national laboratory on the use of baclofen in alcohol dependence for over ten years, should let this original therapeutic option available to patients. However, it should update the regulatory framework defining the main conditions of access to treatment for patients based on the latest and highest scientific evidence.
Abstract licence: CC BY
M. Soyka, M. Friede, J. Schnitker
Pharmacopsychiatry, 2016
C. Palpacuer, Renan Duprez, Alexandre Huneau, et al.
Addiction, 2018
H. López-Pelayo, P. Zuluaga, E. Caballeria, et al.
Expert Opinion on Drug Safety, 2019
C. Palpacuer, A. Braillon, F. Naudet
Psychiatry and Clinical Neurosciences, 2020
Guofa Shan, Haixia Lu, Fang Dai, et al.
Medicine, 2023
- Myoclonus
- Etomidate
- Drug-Related Side Effects and Adverse Reactions
Background: This study compared the effectiveness of nalmefene and fentanyl in reducing the incidence and severity of etomidate-induced myoclonus. Methods: One hundred fifty patients were randomized to receive 0.25ug/kg of nalmefene, 1ug/kg of fentanyl, or the same volume of normal saline 3 minutes prior to etomidate-induced anesthesia. The primary observational indexes were the severity level and incidence of etomidate-induced myoclonus, and the secondary observational index included blood pressure, heart rate, and the incidence of adverse effects from anesthesia induction to resuscitation, such as cough, chest wall rigidity, dizziness, nausea, pain after awakening, and intraoperative awareness. Results: The incidence of myoclonus was significantly lower in the nalmefene group (8.0%) than in the fentanyl group (32.0%) (P = .003) and in the normal saline group (72.0%) (P = .000). The severity level of myoclonus in the nalmefene group was significantly lower than the fentanyl group (P = .001) and normal saline group (P = .000). Meanwhile, the incidences of cough and chest wall rigidity during anesthesia induction were significantly lower in the nalmefene group compared with the fentanyl group (P = .003, P = .027). There were no statistically significant differences in heart rate and mean arterial pressure among the 3 gruops (P > .05). There was no difference in the incidence of adverse effects among the 3 groups during recovery from anesthesia (P > .05). Conclusion: Intravenous injection of 0.25ug/kg of nalmefene 3 minutes prior to etomidate is more effective in preventing etomidate-induced myoclonus during general anesthesia than 1ug/kg of fentanyl.
Abstract licence: CC BY-NC 4.0
Jin Wang, K. Zheng, Quan Wen, et al.
Heliyon, 2023
Sources: aggregated from Europe PMC (EMBL-EBI), OpenAlex, Crossref, PubMed and other open scholarly databases. Retracted articles are excluded. Study information is provided for research purposes and does not constitute medical advice.
Pharmacology and chemical data from DrugBank
Key facts
Drug status
Approved
Major interactions
None known
Half-life
12.5 hours
Mechanism
The opioid system consists of three opioid receptors - mu (μ), delta (δ), and ka…
Food interactions
1 warning
Human targets
3 targets
Data: DrugBank · CC BY-NC 4.0
Pharmacokinetics at a glance
Absorption
18.06 mg
Half-life
12.5 hours
[L1024]
…
Protein binding
30%
[L1024][L40684]
In vitro, 67% (CV 8.7%)…
Volume of distribution
1 mg
Metabolism
10%
Elimination
54%
Clearance
169 L/h
[L1024]
…
Pharmacokinetic data: DrugBank · CC BY-NC 4.0
In Europe, nalmefene oral tablets are used to reduce alcohol consumption in adults with alcohol dependence.[L1024] Nalmefene was approved in the United States in 1995 as an antidote for opioid overdose.[A245839] Nalmefene injection is used to manage known or suspected opioid overdose. It is used for complete or partial reversal of opioid drug effects, including respiratory depression, induced by either natural or synthetic opioids.[L40684] The nasal spray formulation of nalmefene was approved by the FDA in May 2023.[L46511]
[L1024]
Nalmefene injection and nasal spray are indicated for the complete or partial reversal of opioid drug effects, including respiratory depression, induced by either natural or synthetic opioids.
They are also indicated in the management of known or suspected opioid overdose.
[L40684][L46511]
Nalmefene injection can be used for postoperative opioid overdose reversal.
[L40684]
Known interactions with other medicines. Always consult a healthcare professional.
Showing 50 of 787 interactions
[L40699]
In mice, rats, and rabbits, intravenous LD50 values had a range of 15.0-48.5 mg/kg and subcutaneous LD50 values were in the range of 157-1150 mg/kg.
[L40704]
Nalmefene was well tolerated and showed no serious toxicity during experimental administration to healthy individuals, even when given at 15 times the highest recommended dose. In a small number of subjects, at doses exceeding the recommended nalmefene injection dose, nalmefene produced symptoms suggestive of reversal of endogenous opioids, such as nausea, chills, myalgia, dysphoria, abdominal cramps, and joint pain. These symptoms can also arise in other narcotic antagonist drugs and they are usually transient in nature and occur at a very low frequency.
[L40684]
Large doses of nalmefene have been used in studies.
For example, one study used doses of nalmefene up to 90 mg/day for 16 weeks in patients diagnosed with pathological gambling. In a study in patients with interstitial cystitis, 20 patients received 108 mg/day of nalmefene for more than two years. Intake of a single dose of 450 mg nalmefene has been reported without changes in blood pressure, heart rate, respiration rate, or body temperature.
There was no unusual pattern of adverse reactions, but the experience is limited. Management of an overdose should be observational and symptomatic.
[L1024]
Nalmefene is an antagonist at the mu and delta-opioid receptors and a partial agonist at the kappa-opioid receptor. As an antagonist, nalmefene blocks ligands from binding to the opioid receptor.[L1024] Animal studies suggest that kappa-opioid receptor signalling blocks acute reward and positive reinforcement effects of drugs with abusive potential by decreasing dopamine in the nucleus accumbens.[A31301] In vivo studies have demonstrated that nalmefene reduces alcohol consumption, possibly by modulating cortico-mesolimbic functions.[L1024] Preclinical studies suggest that nalmefene restores alcohol-induced dysregulations of the MOR/endorphins and the KOR/dynorphin system.[A245834]
Nalmefene has no opioid agonist activity and it is not associated with drug tolerance, physical dependence, or abuse potential.[L40684]
Nalmefene is not known to produce respiratory depression, psychotomimetic effects, or pupillary constriction. No pharmacological activity was observed when nalmefene was administered in the absence of opioid agonists. However, as with all opioid antagonists, nalmefene can produce acute withdrawal symptoms in individuals with opioid dependence. These withdrawal symptoms should be managed with symptomatic and supportive treatment: the administration of large amounts of opioids to patients receiving opioid antagonists in an attempt to overcome a full blockade has resulted in adverse respiratory and circulatory reactions.[L40684]
How the body processes this drug — absorption, distribution, metabolism, and elimination
High-fat meal increased the AUC by 30% and Cmax by 50% and delayed Tmax by 30 min; however, this is unlikely of clinical significance.
[L1024]
Nalmefene exhibits dose-proportional pharmacokinetics following intravenous administration of 0.5 mg to 2 mg. Tmax was 2.3 ± 1.1 hours following intramuscular administration and 1.5 ± 1.2 hours following subcutaneous administration. Therapeutic plasma concentrations are likely to be reached within 5 to 15 minutes after a 1 mg dose in an emergency.
There is variability in the speed of absorption for intramuscular and subcutaneous dosing.
[L40684]
[L1024]
After intravenous administration of 1 mg nalmefene to healthy adult male subjects, plasma concentrations declined biexponentially with redistribution and a terminal elimination half-life of 41 ± 34 minutes and 10.8 ± 5.2 hours, respectively.
[L40684]
[L1024][L40684]
In vitro, 67% (CV 8.7%) of nalmefene was distributed into red blood cells and 39% (CV 6.4%) was distributed into plasma. The whole blood to plasma ratio was 1.3 (CV 6.6%) over the nominal concentration range in whole blood from 0.376 to 30 ng/mL.
[L40684]
[L40684]
Nalmefene readily crosses the blood-brain barrier.
[L1024]
[L1024]
Nalmefene is also metabolized to trace amounts of an N-dealkylated metabolite, which has minimal pharmacological activity.
[L40684]
Nalmefene can undergo dealkylation mediated by CYP3A4/5 to form nornalmefene. Nornalmefene can be further converted to nornalmefene 3-O-glucuronide and nornalmefene 3-sulfate, which are generally inactive metabolites.
[L1024]
Nalmefene can also undergo CYP3A4/5-mediated sulfation to form nalmefene 3-O-sulfate, which retains some pharmacological activity.
However, nalmefene 3-O-sulfate is present in the circulation in less than 10% of that of nalmefene; thus, it is unlikely to be a major contributor to the pharmacological activity of nalmefene.
[L1024]
The plasma concentration-time profile in some subjects suggests that nalmefene undergoes enterohepatic recycling.
[L40684]
[L1024]
About 17% of the dose is excreted in the feces.
[L40684]
[L1024]
Following intravenous administration of 1 mg nalmefene, the systemic clearance of nalmefene was 0.8 ± 0.2 L/hr/kg and the renal clearance was 0.08 ± 0.04 L/hr/kg.
[L40684]
Proteins and enzymes this drug interacts with in the body
Signaling leads to the inhibition of adenylate cyclase activity. Inhibits neurotransmitter release by reducing calcium ion currents and increasing potassium ion conductance. Plays a role in the perception of pain.
Plays a role in mediating reduced physical activity upon treatment with synthetic opioids. Plays a role in the regulation of salivation in response to synthetic opioids. May play a role in arousal and regulation of autonomic and neuroendocrine functions
Inhibits neurotransmitter release by reducing calcium ion currents and increasing potassium ion conductance. Plays a role in the perception of pain and in opiate-mediated analgesia. Plays a role in developing analgesic tolerance to morphine
PMID:10529478 PMID:12589820 PMID:7891175 PMID:7905839 PMID:7957926 PMID:9689128
Receptor for natural and synthetic opioids including morphine, heroin, DAMGO, fentanyl, etorphine, buprenorphin and methadone .
PMID:10529478 PMID:10836142 PMID:12589820 PMID:19300905 PMID:7891175 PMID:7905839 PMID:7957926 PMID:9689128
Also activated by enkephalin peptides, such as Met-enkephalin or Met-enkephalin-Arg-Phe, with higher affinity for Met-enkephalin-Arg-Phe (By similarity). Agonist binding to the receptor induces coupling to an inactive GDP-bound heterotrimeric G-protein complex and subsequent exchange of GDP for GTP in the G-protein alpha subunit leading to dissociation of the G-protein complex with the free GTP-bound G-protein alpha and the G-protein beta-gamma dimer activating downstream cellular effectors .
PMID:7905839
The agonist- and cell type-specific activity is predominantly coupled to pertussis toxin-sensitive G(i) and G(o) G alpha proteins, GNAI1, GNAI2, GNAI3 and GNAO1 isoforms Alpha-1 and Alpha-2, and to a lesser extent to pertussis toxin-insensitive G alpha proteins GNAZ and GNA15 .
PMID:12068084
They mediate an array of downstream cellular responses, including inhibition of adenylate cyclase activity and both N-type and L-type calcium channels, activation of inward rectifying potassium channels, mitogen-activated protein kinase (MAPK), phospholipase C (PLC), phosphoinositide/protein kinase (PKC), phosphoinositide 3-kinase (PI3K) and regulation of NF-kappa-B (By similarity). Also couples to adenylate cyclase stimulatory G alpha proteins (By similarity).
The selective temporal coupling to G-proteins and subsequent signaling can be regulated by RGSZ proteins, such as RGS9, RGS17 and RGS4 (By similarity). Phosphorylation by members of the GPRK subfamily of Ser/Thr protein kinases and association with beta-arrestins is involved in short-term receptor desensitization (By similarity). Beta-arrestins associate with the GPRK-phosphorylated receptor and uncouple it from the G-protein thus terminating signal transduction (By similarity).
The phosphorylated receptor is internalized through endocytosis via clathrin-coated pits which involves beta-arrestins (By similarity). The activation of the ERK pathway occurs either in a G-protein-dependent or a beta-arrestin-dependent manner and is regulated by agonist-specific receptor phosphorylation (By similarity). Acts as a class A G-protein coupled receptor (GPCR) which dissociates from beta-arrestin at or near the plasma membrane and undergoes rapid recycling (By similarity).
Receptor down-regulation pathways are varying with the agonist and occur dependent or independent of G-protein coupling (By similarity). Endogenous ligands induce rapid desensitization, endocytosis and recycling (By similarity). Heterooligomerization with other GPCRs can modulate agonist binding, signaling and trafficking properties (By similarity)
Enzymes involved in drug metabolism — important for understanding drug interactions
ATC N07BB05
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Show
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Linked compound data from DrugBank Open Data (CC BY-NC 4.0)
Nalmefene
Additional database identifiers
ChemSpider
4447642
BindingDB
50045776
ZINC
ZINC000000403529
HUGO Gene Nomenclature Committee (HGNC)
HGNC:8154
GenAtlas
OPRK1
GeneCards
OPRK1
GenBank Gene Database
U11053
GenBank Protein Database
532060
Guide to Pharmacology
318
UniProt Accession
OPRK_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:8153
GenAtlas
OPRD1
GeneCards
OPRD1
GenBank Gene Database
U07882
GenBank Protein Database
27545517
Guide to Pharmacology
317
UniProt Accession
OPRD_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:8156
GenAtlas
OPRM1
GeneCards
OPRM1
GenBank Gene Database
L25119
GenBank Protein Database
452073
Guide to Pharmacology
319
UniProt Accession
OPRM_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:12554
GeneCards
UGT2B7
GenBank Gene Database
J05428
GenBank Protein Database
340080
UniProt Accession
UD2B7_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:12535
GeneCards
UGT1A3
GenBank Gene Database
M84127
GenBank Protein Database
340135
UniProt Accession
UD13_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:12540
GeneCards
UGT1A8
GenBank Gene Database
AF030310
GenBank Protein Database
2613044
UniProt Accession
UD18_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2637
GenAtlas
CYP3A4
GeneCards
CYP3A4
GenBank Gene Database
M18907
Guide to Pharmacology
1337
UniProt Accession
CP3A4_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2638
GenAtlas
CYP3A5
GeneCards
CYP3A5
GenBank Gene Database
J04813
GenBank Protein Database
181346
Guide to Pharmacology
1338
UniProt Accession
CP3A5_HUMAN
DrugBank citations
If you use DrugBank data in your research, please cite:
- DrugBank 6.02024Recommended citationKnox C., Wilson M., Klinger C.M., et alDrugBank 6.0: the DrugBank Knowledgebase for 2024Nucleic Acids Res. 2024 Jan 552(D1):D1265-D1275
- DrugBank 5.02018Wishart D.S., Feunang Y.D., Guo A.C., et alDrugBank 5.0: a major update to the DrugBank database for 2018Nucleic Acids Res. 2017 Nov 846(D1):D1074-D1082
- DrugBank 4.02014Law V., Knox C., Djoumbou Y., et alDrugBank 4.0: shedding new light on drug metabolismNucleic Acids Res. 2014 Jan 142(1):D1091-7
- DrugBank 3.02011Knox C., Law V., Jewison T., et alDrugBank 3.0: a comprehensive resource for 'omics' research on drugsNucleic Acids Res. 2011 Jan39(Database issue):D1035-41
- DrugBank 2.02008Wishart D.S., Knox C., Guo A.C., et alDrugBank: a knowledgebase for drugs, drug actions and drug targets.Nucleic Acids Research2008 Jan36(Database issue):D901-6
- DrugBank 1.02006Wishart D.S., Knox C., Guo A.C., et alDrugBank: a comprehensive resource for in silico drug discovery and exploration.Nucleic Acids Research2006 Jan 134(Database issue):D668-72