How effective are opioid antagonists (naltrexone and nalmefene) in the treatment of alcohol dependence?
Even though the sizes of treatment effects might appear moderate, these results should be seen against the background of the relapsing nature of alcoholism and the limited therapeutic options currently available for its treatment. Naltrexone did not prevent return to any drinking. The drug does not have serious side effects, but tiredness and gastrointestinal symptoms like nausea, stomach pain and loss of appetite are common. In most studies, treatment was provided over a period of 3 months, with follow-up ranging from 3–17 months.
Alcohol affects various brain regions, including the opioid receptor system, which mediates the euphoric and pleasurable effects of alcohol. By blocking alcohol effects at these receptors the opioid antagonists naltrexone and nalmefene can reduce alcohol “liking” and “craving” and thus support alcohol-dependent patients in cutting down their drinking.