Naltrexone is a medication approved to treat Alcohol Use Disorder (AUD). Classified as an opioid antagonist, it works by blocking certain receptors in the brain. Its primary function is to support long-term recovery by reducing the desire to drink alcohol and lessening the reward felt from alcohol consumption. Alcohol Withdrawal Syndrome (AWS) is a distinct medical condition that occurs when a person physically dependent on alcohol abruptly stops or significantly reduces their intake. Naltrexone is intended for the sustained management of AUD after the initial detoxification phase is safely completed.
Naltrexone’s Role in Reducing Cravings
The main therapeutic benefit of Naltrexone is its ability to modify the brain’s response to alcohol, decreasing cravings and preventing relapse. Alcohol consumption stimulates the release of endorphins, which bind to mu-opioid receptors and contribute to the pleasurable effects of drinking. Naltrexone competitively binds to these same receptors, blocking the endorphins from attaching.
By blocking this pathway, Naltrexone diminishes the rewarding feeling experienced from alcohol. This action helps to “uncouple” the positive reinforcement that drives compulsive drinking behavior. The result is a reduction in the intensity of cravings and a lower likelihood of heavy drinking.
Naltrexone and Acute Withdrawal Symptoms
Naltrexone is not used to treat the symptoms of acute alcohol withdrawal and is held until detoxification is finished. Alcohol withdrawal is a serious medical event characterized by central nervous system over-excitability, which Naltrexone does not address. Starting the medication too early can increase the risk of side effects like nausea and vomiting, which are common during initial abstinence.
The recommendation is to wait until the signs of acute withdrawal have fully subsided before beginning Naltrexone treatment. This often means ensuring the patient has been abstinent from alcohol for at least three to seven days. The drug does not prevent life-threatening complications of withdrawal, such as seizures or delirium tremens, and should not be used as a substitute for standard withdrawal care.
Standard Medical Care for Alcohol Withdrawal
Acute alcohol withdrawal requires specific medical treatment to stabilize the patient and prevent severe complications. Standard care relies primarily on highly effective benzodiazepines, such as diazepam or chlordiazepoxide. These medications work by targeting the gamma-aminobutyric acid (GABA) receptors in the brain, substituting for the inhibitory effects of alcohol.
Alcohol dependence causes the central nervous system to become hyper-excitable, and benzodiazepines help to dampen this over-activity. They reduce the severity of symptoms like tremors, anxiety, and agitation, while also preventing seizures and the progression to delirium tremens. Treatment is typically managed in a monitored medical setting, often with a tapering dose over five to seven days. Patients are also often given thiamine and other vitamin supplements to prevent Wernicke’s encephalopathy, a severe neurological complication.
Oral Versus Injectable Naltrexone
Naltrexone is available in two main formulations for the treatment of AUD: a daily oral tablet and an extended-release intramuscular injection. The oral form is taken once a day, typically at a 50 mg dose, offering flexibility and a lower cost. The extended-release injection, sold under the brand name Vivitrol, is administered once a month, usually at a 380 mg dose.
Both formulations have demonstrated similar effectiveness in reducing heavy drinking days and overall alcohol consumption. The choice often comes down to patient preference and adherence concerns. The injectable option may be preferred for individuals who struggle with remembering to take a daily pill, ensuring consistent medication levels. Conversely, the oral form is more accessible and less expensive than the monthly injection.