Naltrexone (ReVia) Treatment

Recent progress in understanding the biological basis of alcoholism has led to a proliferation of new treatment options. For instance, naltrexone (or ReVia), which was previously only available for the treatment of opiate addiction, is currently being used to combat alcoholism.

Mechanism of the Drug

Naltrexone has proven effective in reducing the euphoria that alcoholics experience when drinking. The drug works by blocking opioid receptors located in the brain. When the opioid receptors are blocked, the individual experiences reduced alcohol-related euphoria and a diminished desire to drink, thereby breaking the vicious reinforcement cycle that accompanies alcoholism. Alcohol consumption becomes less appealing due to the the reduction of the reinforcing dopamine reward.

Effectiveness of Naltrexone

Several studies have been done examining the effectiveness of naltrexone and impact on relapse rates. Research shows that naltrexone reduces alcohol intake and the lowers the rate of relapse among alcohol dependent and alcohol misusing individuals.

During initial studies, 60% of the placebo group relapsed while only 40% of the naltrexone group returned to drinking. A clinical trial at the University of Pennsylvania found that while 85% of the placebo subjects slipped into relapse, only 50% of naltrexone subjects relapsed. The Pennsylvania study was replicated by O'Malley et al. (1996), who showed that naltrexone may decrease relapse rates, number of drinking days, and total number of drinks consumed.

Other researchers found that the number of abstinent patients in the naltrexone group was twice the rate of the acamprosate group, and time until first relapse was longer in naltrexone patients than acamprosate patients. At the end of this 12-month study, 41% of the naltrexone group had not relapsed while 54% were abstinent, compared to only 17% not relapsing and only 27% abstinent in the acamprosate group.

Not only was the addictive cycle of alcohol broken for many using naltrexone, those who did relapse reported a decrease in the euphoric feeling that alcohol characteristically provides. In some clinical trials evaluating the efficacy of naltrexone, patients who were prescribed naltrexone were two times as likely to remain abstinent than those on placebo. Although naltrexone appears to have some efficacy reducing alcohol consumption, its specific role in treating alcoholism needs to be more clearly defined.

Using Naltrexone in a Combined Treatment Approach

Naltrexone has been found to effectively treat alcoholism, but it is not a “magic pill” that should be prescribed as the sole treatment vehicle. Naltrexone may be beneficial in treating alcoholism, but only when used in conjunction with successful behavioral therapy. In fact, success rates for naltrexone appear to be greater when pharmacotherapy is combined with psychosocial treatment. Therefore, patients taking naltrexone are encouraged to continue the self-empowerment and self-help philosophy of traditional psychosocial methods (i.e. 12-step program) and support groups.

Prescribing Naltrexone

Naltrexone is approved by the Food and Drug Administration (FDA) for individuals that have been diagnosed as stable, alcohol dependent, not currently using opioids, (such as heroin or pain medication) and do not suffer from active hepatitis or liver disease. Caution is recommended when prescribing naltrexone since it can lead to liver toxicity if taken at higher than recommended doses. Naltrexone is only one aspect of treatment -- potential patients should also undergo psychosocial treatment that has sobriety as its ultimate goal.

Dosage

Although treatment should be tailored to a patient's particular needs, dosage is typically 12.5 mg/day during the initial week, then 25 mg/day the second week, and finally 50 mg/day. This gradual "step up" method will decrease the possibility of adverse side effects (namely nausea) and increase the likelihood that the patient will remain on the medication.

Duration

Treatment duration for naltrexone generally lasts three months. Identification Cards stating that the patient is currently taking naltrexone should be given to the patient and carried at all times. Patients with scheduled operations or dental work should discontinue naltrexone three days before undergoing the procedure, then resume naltrexone no less than 5-7 days following administration of the opiate analgesic.

Side Effects

Side effects attributed to naltrexone are rare, except in cases when the patient suffers from preexisting hepatic injury. Because of this possibility, a patient should undergo baseline liver function testing before being prescribed naltrexone, and any dose greater than the usual amount should involve continued monitoring of a patient's liver functioning. However, a patient should be reassured that naltrexone is less harmful to the liver than the continued consumption of alcohol.

Discontinuing the Drug

Discontinuing naltrexone can be as problematic for the patient as stopping alcohol. Remember, this is a significant psychological shift for individuals that are accustomed to using a liquid to help them relax, a pill to help them sleep, a powder to get them going, and most recently, taking a pill to not use the liquid. Some patients' “drug culture” instills a reliance on substances in general, making it difficult for them to become completely substance free.

Precautions

Pregnant and breast feeding women should avoid naltrexone until further research is done on how naltrexone effects breast milk, hormonal status, and prolactin.