Acamprosate (brand: Campral) “is thought to reduce symptoms of protracted abstinence [i.e., withdrawal] by counteracting the imbalance between the glutamatergic and GABAergic systems associated with chronic alcohol exposure and alcohol withdrawal.” (SAMHSA: Medication for the Treatment of Alcohol Use Disorder: A Brief Guide).
It is more helpful for preventing recurrence of alcohol use in individuals who have achieved abstinence or significantly cut down and are experiencing cravings due to signs of protracted withdrawal (eg., anxiety, insomnia, irritability). It is dosed 666mg PO three times daily, and it is contraindicated in individuals with serious renal disease.
Naltrexone is an opioid receptor antagonist that comes in oral (brands: ReVia, Depade) and long-acting injectable (brand: Vivitrol) formulations. Both formulations are indicated for alcohol use disorder, and the long-acting injectable formulation is indicated to treat opioid use disorder. For alcohol use disorder, naltrexone works by blocking opioid transmission in the brain’s reward pathway, thereby reducing the pleasurable effects of drinking alcohol. It is helpful for both reducing recurrence in someone who is abstinent from alcohol and reducing binges/heavy drinking episodes in someone who is not abstinent. For opioid use disorder, it blocks the rewarding effects of opioid use and protects against overdose. It also may reduce opioid cravings over time. The oral formulations are dosed 50mg PO daily, 100mg PO every other day, or 150mg PO every third day. The long-acting injection is given 380mg IM every 4 weeks. Due to the risk of medically serious protracted opioid withdrawal, naltrexone – especially the long-acting injection – is contraindicated in people who need to be on opioids for pain, in people who have used opioids in the past 7-10 days, and in people who have a positive urine drug screen for opioids and/or fail a naloxone challenge test. It is also contraindicated in people with acute and/or serious liver disease, in people with an allergy to naltrexone, and during pregnancy and nursing.
Disulfiram (brand: Antabuse) is an older medication that may be worth considering in some patients to help them remain in recovery. It produces a sensitivity to alcohol, which results in a highly unpleasant reaction when the individual under treatment ingests alcohol. This reaction can range from a flush and throbbing in the head and neck to nausea, vomiting, breathing difficulty, chest pain, heart failure and possible death. Disulfiram produces this reaction by blocking the oxidation of alcohol. A product of this oxidation is acetaldehyde. If alcohol is consumed after disulfiram is taken, the metabolism of the alcohol stops at the point of acetaldehyde production and there will be an increase in the concentration of acetaldehyde 5 - 10 times higher than in normal alcohol metabolism. Disulfiram is doses 500mg PO daily for 1-2 weeks, and then 250mg PO daily. This medication cannot be given to anyone with a history of severe heart disease, psychosis, allergy to disulfiram, pregnancy, paraldehyde use, or metronidazole use. It must be used with caution in the patient with a history of diabetes, seizures, and liver disease. It works best for individuals in regular psychosocial treatment with robust family/social supports.