Nalmefene

Products

Nalmefene is commercially available in the form of film-coated tablets (Selincro). It was registered in many countries in 2014.

Structure and properties

Nalmefene (C21H25NO3, Mr = 339.4 g/mol) is structurally closely related to naltrexone, from which it is derived. In the drug product, it is present as nalmefene hydrochloride and dihydrate, a white crystalline powder that is highly soluble in water. It is also known as nalmefene and nalmetrene.

Effects

Nalmefene (ATC N07BB05) has opioid antagonistic properties at the μ- and δ-receptors and is a partial agonist at the κ-receptor. It is therefore referred to as an opioid receptor modulator. Its effects start in the brain‘s reward system. The drug reduces alcohol consumption in alcohol dependence.

Indications

  • To reduce alcohol consumption in adult patients with alcohol dependence whose alcohol consumption is at a high risk level, in whom physical withdrawal symptoms are not present, and for whom immediate detoxification is not required.
  • To reverse the effects of opioids (as a solution for injection, Revex, USA).

Dosage

According to the professional information. Tablets are taken as needed, preferably one to two hours before expected alcohol consumption. Tablets are administered no more than once daily, regardless of meals.

Contraindications

  • Hypersensitivity
  • Concurrent use of opioids (analgesics).
  • Existing or recent opioid dependence.
  • Acute opioid withdrawal symptoms
  • Recent opioid use
  • Severe hepatic impairment
  • Severe renal dysfunction
  • Recent acute alcohol withdrawal symptoms (such as hallucinations, seizures, delirium tremens)

For complete precautions, see the drug label.

Interactions

Nalmefene is metabolized primarily by UGT2B7 to nalmefene-3-O-glucuronide. Drug-drug interactions are possible with UGT2B7 inhibitors. These include, for example, diclofenac, fluconazole, medroxyprogesterone acetate, and meclofenamic acid. Interactions may also occur with UGT inducers. Opioids may reverse the effects of nalmefene.

Adverse Effects

The most common potential adverse effects include nausea, dizziness, insomnia, and headache. Unlike naltrexone, nalmefene is not reported to be toxic to the liver.