FDA-approved Medication for Alcohol Dependence

Naltrexone for Alcoholism

Naltrexone was approved by the FDA as a treatment for Alcohol Dependence in 1994.  However, it was initially approved for the treatment of Opioid Dependence in 1984, due to the fact that the medication works by blocking the effects of opioids.  This includes naturally occurring opiates in the brain known as Endorphin.  When alcohol is consumed, normally these endorphins are released, which causes the drinker to experience please.  When these receptors are blocked, the experience of enjoyment is less when alcohol is consumed.

Evidence has demonstrated that when Naltrexone is combined with counseling and other therapeutic interventions, it can decrease

  • The amount of alcohol consumed during one occasion (i.e. binges).
  • The number of days spent drinking
  • Drinking that results in negative consequences

Naltrexone does not make you sick when you combine it with alcohol, the way Antabuse (disulfiram) does.  It does not alter the metabolism or absorption of alcohol in any way, nor does it prevent patients from becoming intoxicated if they drink alcohol.

Because Naltrexone blocks opioid receptors, opiate pain medications such as Morphine, Oxycodone, Percocet,  and Vicodin will  not be effective.  If treatment with opioids is necessary, the naltrexone will need to be stopped for 2 to 3 days prior to starting the opiods.  Patients should wait 5-10 days after taking Naltrexone before starting an opiate.

Naltrexone does not affect over-the-counter pain medications such as Ibuprofen (Advil), Acetaminophen (Tylenol), or aspirin.

Naltrexone Side Effects

Naltrexone is generally well tolerated, but like all medications, it has the potential to cause side effects. The frequency of serious side effects is very low. The most common side effects are gastrointestinal, including upset stomach, nausea, vomiting, and diarrhea. The frequency of side effects is below:

  • nausea (10%)
  • headache (7%)
  • dizziness (4%)
  • nervousness (4%)
  • fatigue (4%)
  • insomnia (3%)
  • vomiting (3%)
  • anxiety (2%)
  • somnolence (2%)

Most likely, you won’t have any side effects, but if you do, they usually go away with continued use. There are a few things that can be done, if a side effect persists:

1. Lower the dose. This will give the body time to adjust to the new medication. Once you feel comfortable, you can try increasing it back to a more therapeutic dose.
2. Divide the dose. Instead of taking 50 mg once daily, you could take 25 mg twice daily.
3. Take with food.
4. Combine the naltrexone with an over-the-counter medication that addresses the side effect. Usually this means taking Pepto-Bismol.

Naltrexone in Pregnancy

It is in Pregnancy Category C, which officially means, “Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.”

For obvious reasons, it is not easy to design a conclusive study that involves giving pregnant woman various medications.

Initial Medical Workup

Prior to starting Naltrexone, it is generally a good idea to have the following:

  • Liver Functioning Tests (LFT)
  • Physical Examination (if indicated)
  • Pregnancy Test

After 1 month of taking Naltrexone, a follow-up LFT can be ordered.  Based on the results, additional labs can be ordered every 3 to 6 months.  More frequent monitoring may be necessary if there is liver damage or other medical concern.

Research has demonstrated that liver functioning generally improves in patients taking Naltrexone, because alcohol is far more damaging to the liver.


The usual dosage for Naltrexone is 50 mg daily.  It may be appropriate to start at 25 mg daily for several days, in order to give your body time to adjust to the medication.  This reduces the likelihood of side effects.

Occasionally, a patient may need doses higher than 50 mg daily.  Even at this dose, the available evidence shows that Naltrexone is safe, well tolerated, and effective.  Prior to adjusting the dosage, additional Liver Function Tests should be obtained.

It is recommended that patients taking Naltrexone carry a safety identification card indicating that they are taking the medication, in case of an emergency.