Acamprosate, sold under the brand name Campral, is a medication used along with counselling to treat alcohol use disorder.Acamprosate is thought to stabilize chemical signaling in the brain that would otherwise be disrupted by alcohol withdrawal. When used alone, acamprosate is not an effective therapy for alcohol use disorder in most individuals; studies have found that acamprosate works best when used in combination with psychosocial support since the drug facilitates a reduction in alcohol consumption as well as full abstinence.Serious side effects include  allergic reactions, abnormal heart rhythms, and low or high blood pressure, while less serious side effects include headaches, insomnia, and impotence. Diarrhea is the most common side-effect. Acamprosate should not be taken by people with kidney problems or allergies to the drug.Until it became generic in the United States, Campral was manufactured and marketed in the United States by Forest Laboratories, while Merck KGaA markets it outside the US. Medical uses
Acamprosate is useful when used along with counseling in the treatment of alcohol use disorder. Over three to twelve months it increases the number of people who do not drink at all and the number of days without alcohol. It appears to work as well as naltrexone for maintenance of abstinence from alcohol, however naltrexone works slightly better for reducing alcohol cravings and heavy drinking, and acamprosate tends to work more poorly outside of Europe where treatment services are less robust.
The effects on the NMDA complex are dose-dependent; the product appears to enhance receptor activation at low concentrations, while inhibiting it when consumed in higher amounts, which counters the excessive activation of NMDA receptors in the context of alcohol withdrawal.The product also increases the endogenous production of taurine.Ethanol and benzodiazepines act on the central nervous system by binding to the GABAA receptor, increasing the effects of the inhibitory neurotransmitter GABA (i.e., they act as positive allosteric modulators at these receptors). In alcohol use disorder, one of the main mechanisms of tolerance is attributed to GABAA receptors becoming downregulated (i.e. these receptors become less sensitive to GABA). When alcohol is no longer consumed, these down-regulated GABAA receptor complexes are so insensitive to GABA that the typical amount of GABA produced has little effect, leading to physical withdrawal symptoms; since GABA normally inhibits neural firing, GABAA receptor desensitization results in unopposed excitatory neurotransmission (i.e., fewer inhibitory postsynaptic potentials occur through GABAA receptors), leading to neuronal over-excitation (i.e., more action potentials in the postsynaptic neuron). One of acamprosates mechanisms of action is the enhancement of GABA signaling at GABAA receptors via positive allosteric receptor modulation. It has been purported to open the chloride ion channel in a novel way as it does not require GABA as a cofactor, making it less liable for dependence than benzodiazepines.