Naltrexone interactions: Alcohol, medications, and other factors

Before you start treatment with naltrexone oral tablet, tell your doctor and pharmacist which prescription, over-the-counter, and other medications you take. By sharing this information with them, you may help prevent possible interactions. (To learn whether naltrexone interacts with supplements, herbs, or vitamins, see the “Naltrexone and other interactions” section below.)

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Here’s a table of drugs that can interact with naltrexone. Keep in mind that this table doesn’t include all drugs that may interact with the drug. Some of these interactions are described in detail just below in “Drug interactions in depth.”

* For details about this interaction, see the “When to avoid naltrexone” section below.
† For details about this interaction, see the “Drug interactions in depth” section below.

In some cases, factors or conditions could prevent your doctor from prescribing naltrexone oral tablet due to the risk of harm. These are known as contraindications. Naltrexone contraindications include:

Having recently taken or become dependent on opioids

Doctors will not typically prescribe naltrexone to people who’ve recently taken opioids or become dependent on opioids. This is because taking naltrexone in these situations could lead to opioid withdrawal.

Opioid withdrawal describes uncomfortable side effects that may occur after stopping an opioid that your body has become dependent on. With opioid dependence, your body needs the opioid to function as it typically would. Examples of withdrawal symptoms include abdominal pain, body aches, vomiting, and diarrhea.

Opioids may be prescribed for many conditions, including pain, cough, diarrhea, and OUD. Examples of opioids include:

• oxycodone (Oxycontin, Xtampza ER, others)
• hydrocodone (Hysingla ER)
• codeine/promethazine
• diphenoxylate/atropine (Lomotil)
• methadone (Methadose)
• buprenorphine (Brixadi, Sublocade, others)

Naltrexone is prescribed for OUD. However, your doctor may not have you start naltrexone treatment until the opioid is gone from your system. They’ll typically have you wait at least 7–10 days after your last opioid dose. If you’re switching from methadone or buprenorphine, your doctor may have you wait at least 2 weeks after your last dose.

Before you start naltrexone, your doctor may give you tests to check whether opioids are in your system. These include a naloxone* challenge test and a urine drug test. If the test results suggest that opioids are still in your system, your doctor may delay your naltrexone treatment. They’ll typically have you wait until the test results confirm that your system no longer contains opioids.

If you have questions about this, talk with your doctor before taking naltrexone. They’ll tell you when it’s safe to begin naltrexone treatment.

* Naloxone (Narcan, Zimhi, others) is given in an emergency to help reverse the effects of an opioid overdose.

Having opioid withdrawal symptoms

Doctors typically will not prescribe naltrexone for people having symptoms of opioid withdrawal. This describes having uncomfortable side effects after stopping an opioid that your body has become dependent on. Examples of these symptoms include abdominal pain, body aches, vomiting, and diarrhea.

Starting naltrexone during this time may worsen opioid withdrawal symptoms. In extreme cases, worsened symptoms could be life threatening or require treatment in a hospital.

If you’re having symptoms of opioid withdrawal, talk with your doctor before taking naltrexone. They’ll tell you when it’s safe to begin naltrexone treatment.

Having had an allergic reaction to naltrexone or any of its ingredients

If you’ve had an allergic reaction to naltrexone or any of its ingredients, your doctor will likely not prescribe the drug. Taking naltrexone could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.

Note: Before you start treatment with naltrexone, it’s important to tell your doctor if these contraindications apply to you. They can determine whether to prescribe naltrexone.

There aren’t any known interactions between naltrexone oral tablet and alcohol. However, your doctor will advise you to avoid alcohol consumption while taking naltrexone for AUD.

Your doctor may also advise you to avoid or limit alcohol consumption while taking naltrexone for OUD. This is because naltrexone may also cause liver damage as a side effect. Consuming large amounts of alcohol can also cause liver damage, so drinking alcohol during naltrexone treatment may increase the risk of liver damage.

If you have concerns about limiting or avoiding alcohol while you’re taking naltrexone, talk with your doctor.

Here’s a closer look at certain drug interactions of naltrexone oral tablet.

Other opioid antagonists

Naltrexone belongs to a drug class called opioid antagonists. Certain opioid antagonists are prescribed for AUD and OUD. Others are prescribed for opioid overdose and opioid-induced constipation.

Interaction result: Taking naltrexone with another opioid antagonist could increase the risk of side effects from naltrexone and the other opioid antagonist. Taking them together could also increase the effect of either drug.

Interaction explained: Naltrexone and other opioid antagonists work by blocking opioid receptors (binding sites) in the body. In this way, these drugs prevent opioids from attaching to the receptors. They may also reverse the effect of any opioid that’s already in your system. Taking these medications together further increases these effects.

Because naltrexone and other opioid antagonists work similarly, these drugs may cause some of the same side effects. Examples include headache, nausea, and opioid withdrawal. Taking these medications together further increases the risk of these side effects.

Examples of other opioid antagonist drugs: Here are some opioid antagonists that may interact with naltrexone:

• naldemedine (Symproic)
• nalmefene (Opvee)
• naloxegol (Movantik)
• naloxone (Narcan, Zimhi, others)
• other forms of naltrexone (Vivitrol)

Steps you or your doctor may take: Before starting naltrexone, tell your doctor if you’re taking an opioid antagonist. They may advise you not to take these medications together. Your doctor can tell you which treatment option may be the right one for you.

To learn more about naltrexone and other opioid antagonists, talk with your doctor or pharmacist.

Thioridazine

Thioridazine is an antipsychotic drug that’s prescribed for schizophrenia.

Interaction result: Taking naltrexone with thioridazine could increase the risk of sleepiness as a side effect of either drug.

Interaction explained: When taken individually, naltrexone and thioridazine may cause sleepiness as a side effect. Taking these medications together further increases this effect. To learn more about the side effects of naltrexone, see this article.

Steps you or your doctor may take: Before taking naltrexone, be sure your doctor knows if you’re taking thioridazine. They can advise you about whether it’s safe to take these medications together.

To learn more about naltrexone and thioridazine, talk with your doctor or pharmacist.

Disulfiram

As with naltrexone, disulfiram is prescribed for AUD.

Interaction result: Taking naltrexone with disulfiram could increase the risk of liver problems as a side effect of either drug.

Interaction explained: Both naltrexone and disulfiram may cause liver problems as a side effect. If you take these medications together, your risk of liver problems may be even greater. To learn more about naltrexone’s side effects, see this article.

Steps you or your doctor may take: Before starting treatment with naltrexone, tell your doctor if you’re taking disulfiram. They may advise you not to take these medications together. Your doctor can tell you whether naltrexone or disulfiram may be the right treatment option for you.

If your doctor prescribes naltrexone with disulfiram, watch closely for symptoms of liver problems. Examples include jaundice, abdominal pain, fatigue, and dark urine. Your doctor can recommend what to do if you have these symptoms.

To learn more about naltrexone and disulfiram, talk with your doctor or pharmacist.

Naltrexone oral tablet may have other interactions, such as with supplements, foods, vaccines, or even lab tests. You’ll find details below. Keep in mind that the following information does not include all other possible interactions with naltrexone.

Naltrexone and supplements

It’s possible for drugs to interact with supplements, such as vitamins and herbs.

Naltrexone and herbs

There are no specific reports of herbs interacting with naltrexone. However, that doesn’t mean herbal interactions won’t occur or be recognized in the future. So it’s important to check with your doctor or pharmacist before taking any of these products during naltrexone treatment.

Naltrexone and vitamins

There are no specific reports of vitamins interacting with naltrexone. However, that doesn’t mean vitamin interactions won’t occur or be recognized in the future. For this reason, you should talk with your doctor or pharmacist before taking any vitamin product with naltrexone.

Naltrexone and food

There are no reports of food interactions with naltrexone. If you’d like to learn more about eating certain foods during treatment with naltrexone, talk with your doctor.

Naltrexone and vaccines

There aren’t any known interactions between naltrexone and vaccines. You can ask your doctor or pharmacist whether you’re due for any vaccines.

Naltrexone interactions with lab tests

Naltrexone may interfere with the results of lab tests that check for the presence of opioids. Because of this, it’s important to tell the person giving you the test (such as a urine drug test) that you’re taking naltrexone.

For additional information, talk with your doctor or pharmacist.

NALTREXONE INTERACTION WITH CANNABIS OR CBD

Cannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have been specifically reported to interact with certain drugs containing naltrexone.

Taking naltrexone with cannabis products could increase the effects of cannabis.

Before you start treatment with naltrexone, tell your doctor and pharmacist if you use cannabis. By sharing this information with them, you may help prevent possible interactions.

Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.

Certain medical conditions and other factors may increase the risk of interactions with naltrexone oral tablet. Before you take this drug, be sure to talk with your doctor about your health history. Naltrexone may not be the right treatment option for you if you have certain medical conditions or other factors affecting your health.

Health conditions or factors that might interact with naltrexone include:

• Recently taking opioids or having become dependent on opioids: Doctors typically will not prescribe naltrexone to people who’ve recently taken opioids or become dependent on opioids. For details, see the “When to avoid naltrexone” section above.
• Current opioid withdrawal symptoms: Doctors typically will not prescribe naltrexone for people having symptoms of opioid withdrawal. For details, see the “When to avoid naltrexone” section above.
• Kidney problems: Before starting treatment with naltrexone, tell your doctor if you have a kidney problem. An example is kidney failure. Having a kidney problem can lead to a high level of naltrexone in your system, increasing your risk of side effects. Your doctor will recommend whether naltrexone is a safe treatment option.
• Liver problems: Before taking naltrexone, tell your doctor if you have a liver problem, such as cirrhosis (liver scarring). Having a liver problem can raise the level of naltrexone in your system, increasing your risk of side effects. Naltrexone may also cause liver damage as a side effect, which may worsen any liver problem you already have. Your doctor will advise you on whether naltrexone is a safe treatment option.
• Allergic reaction: If you’ve had an allergic reaction to naltrexone or any of its ingredients, your doctor will likely not prescribe the drug. Taking naltrexone could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.
• Breastfeeding: It’s not known whether it’s safe to take naltrexone while breastfeeding. There isn’t enough information to determine whether the drug passes into breast milk or what effects naltrexone may have on a child who is breastfed. If you’re breastfeeding or planning to, talk with your doctor before taking naltrexone. They can talk with you about treatment options and ways to feed your child.
• Pregnancy: There haven’t been enough clinical trials to determine whether naltrexone is safe to take while pregnant. Animal studies show that the drug may cause pregnancy loss. However, it’s important to note that animal studies don’t always indicate what may happen in humans. If you’re pregnant or planning to become pregnant, tell your doctor before starting naltrexone. They can advise you on the right treatment plan for you.

Here are some frequently asked questions about naltrexone oral tablet and possible interactions.

Are low dose naltrexone interactions different from those of higher doses?

Possibly, but it’s not known for certain. The drug’s manufacturer hasn’t reported interactions for low dose naltrexone or compared them with interactions of higher doses.

Low dose naltrexone may be prescribed off-label for conditions other than AUD and OUD. Off-label drug use is when a drug is prescribed for a purpose other than what it’s approved for.

To learn more about possible interactions with low dose naltrexone, talk with your doctor or pharmacist. For details about naltrexone and dosage, you can view this article.

You can take certain steps to help prevent interactions with naltrexone oral tablet. Your doctor and pharmacist are key resources, so reach out to them before starting treatment. For example, you should plan to do the following:

• Let them know if you drink alcohol or use cannabis.
• Tell them about any other medications you take, as well as any supplements, herbs, and vitamins.
• Create a medication list, which your doctor and pharmacist can help you fill out.

It’s also important to read the naltrexone label and other paperwork that may come with the drug. The label may have colored stickers that mention an interaction. And the paperwork, sometimes called the medication guide or patient package insert, may contain details about interactions.

If naltrexone doesn’t come with paperwork, you can ask your pharmacist to print a copy. If you need help reading or understanding this information, ask your doctor or pharmacist.

You can also help prevent interactions with naltrexone by taking it exactly as your doctor prescribes.

Besides learning about interactions, you may want to find out more about naltrexone oral tablet. These resources might help:

• Overview of naltrexone: For a general overview of naltrexone, you can see this article.
• Side effects: If you’re interested in the side effects of naltrexone, see this article. Another option is to refer to the drug’s prescribing information.
• Dosage specifics: To learn about the dosage of naltrexone, see this article.
• Facts about your condition: To learn more about the conditions naltrexone treats, see our list of articles on alcohol and drug addiction.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.