How do naltrexone and acamprosate help reduce relapse in alcoholism?

Naltrexone and acamprosate are pharmacological tools used to help reduce relapse in individuals with alcohol use disorder, though their mechanisms of action differ significantly.12

• Naltrexone: This medication acts as an opioid receptor antagonist. Because alcohol consumption stimulates the brain’s reward pathways through endogenous opioid signaling, naltrexone blocks these receptors to disrupt the transmission of signals that produce euphoric and rewarding effects. By limiting these reinforcing sensations, it helps diminish the urge to drink and reduces cravings.31

• Acamprosate: Also known as calcium acetylhomotaurinate, this agent functions as a modulator of gamma-aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA) receptors.2

While both medications have been shown to be effective in reducing relapse over periods of up to a year, there is no evidence that either agent reduces the risk of relapse over the long term.2