Nalmefene

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.