Brixadi (buprenorphine) is a prescription drug used to treat opioid use disorder in adults. Brixadi can cause side effects that range from mild to serious. Examples include headache, constipation, and nausea.

Specifically, Brixadi is prescribed for opioid use disorder in adults who have already received another buprenorphine treatment. Brixadi is prescribed together with counseling and psychosocial support.

The active ingredient in Brixadi is buprenorphine. (An active ingredient is what makes a drug work.) Brixadi comes as a liquid solution in a prefilled syringe. You’ll receive the drug as an injection under your skin. It’s given by a healthcare professional in a clinic or doctor’s office.

Keep reading to learn about the common, mild, and serious side effects Brixadi can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects during Brixadi treatment. Examples of the drug’s more commonly reported side effects include:

  • pain, itchiness, redness, or deepening of skin color at the injection site
  • headache
  • constipation
  • nausea
  • insomnia

Mild side effects have been reported with Brixadi. These include:

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop Brixadi treatment unless your doctor recommends it.

Brixadi may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* To learn more about this side effect, see the “Side effects explained” section below.

Serious side effects have been reported with Brixadi. These include:

If you develop serious side effects during Brixadi treatment, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* Dependence is when your body gets used to a drug and needs it for you to function as usual. Withdrawal symptoms are side effects caused by suddenly stopping a drug.
† To learn more about this side effect, see the “Side effects explained” section below.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Brixadi, visit MedWatch.

Get answers to some frequently asked questions about Brixadi’s side effects.

How do side effects of Brixadi compare with those of Sublocade?

Brixadi and Sublocade are both long-acting injections used to help treat opioid use disorder. Both drugs contain the same active ingredient, buprenorphine. (An active ingredient is what makes a drug work.) These drugs can cause similar side effects.

To learn more about how Brixadi and Sublocade compare, talk with your doctor.

Does Brixadi cause long-term side effects?

It’s possible. Long-term side effects include those that may start at any time you’re taking a drug, even if you’ve taken it for a long time. They also include side effects that may not go away, even after you stop treatment with the drug.

Examples of long-term side effects reported in Brixadi’s studies include:

  • adrenal insufficiency
  • liver problems
  • physical dependence, which can lead to withdrawal symptoms if Brixadi is stopped suddenly

Talk with your doctor to learn more about possible side effects of Brixadi and how long they may last.

Learn more about some of the side effects Brixadi may cause.

Risk of serious harm or death if injected into a vein

Brixadi is meant to be injected under your skin. The medication forms a crystalline gel under your skin that slowly releases the medication into your body over time.

If injected into a vein, Brixadi can form a crystalline gel in your vein. This can cause serious harm. For example, the gel can block the vein or cause tissue damage in the local area. The gel can also travel in your bloodstream and block blood supply to vital organs such as your lungs. This can lead to death.

What might help

Due to the risk of serious harm or death if the drug is injected into a vein, Brixadi must be injected only by a specially certified healthcare professional.

Brixadi is available only through a risk evaluation and mitigation strategy (REMS) program. Only healthcare professionals certified by the REMS program can get, prescribe, and administer Brixadi.

For more information about the Brixadi REMS program, visit the website, call 833-274-9234, or talk with your doctor.

CNS depression and respiratory depression

Brixadi is an opioid drug that can cause CNS and respiratory depression. With CNS depression, you have slowed activity in your brain and nervous system. In severe cases, this can lead to coma. With respiratory depression, your breathing becomes slow and shallow. In severe cases, your breathing can stop. These side effects can be life threatening or even fatal.

CNS and respiratory depression can cause symptoms such as:

  • severe sleepiness
  • confusion
  • coordination problems
  • slurred speech
  • slow, shallow, or weak breathing
  • loss of consciousness

It’s not known how often these side effects occurred in studies of Brixadi. However, Brixadi is injected by a healthcare professional, and the risk of these side effects when the drug is given this way are low.

Factors that increase the risk of CNS and respiratory depression with Brixadi include misusing the medication by self-injecting it. Other factors include drinking alcohol or taking other CNS depressant drugs with Brixadi. Examples of other CNS depressants include:

What might help

You should avoid drinking alcohol during Brixadi treatment. You should also avoid taking opioids and other CNS depressants unless your doctor has prescribed them.

Your doctor will likely recommend keeping Narcan (naloxone) on hand throughout your Brixadi treatment for opioid use disorder. Narcan is a nasal spray that can be used in an emergency to treat opioid overdose. It reverses the effects of opioids and relieves CNS and respiratory depression.

Your doctor can prescribe Narcan, or you can buy it over the counter from pharmacies. You should let people you live with and those close to you know where you keep Narcan. If you have symptoms of CNS or respiratory depression, another person will need to administer Narcan for you. They should call 911 or your local emergency number after giving you the drug. Multiple doses of Narcan may be needed.

If you have questions or concerns about the risk of CNS or respiratory depression with Brixadi, talk with your doctor or pharmacist. You can also talk with your doctor or pharmacist about Narcan.

Allergic reaction

Like most drugs, Brixadi can cause an allergic reaction in some people. But this side effect was rarely reported in the drug’s studies. Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin (usually in your eyelids, lips, hands, or feet)
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an oral antihistamine, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Brixadi, they’ll decide whether you should continue treatment.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Brixadi, they may have you switch to a different treatment.

Keeping track of side effects

During your Brixadi treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start treatment with a new drug or combination of drugs.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Taking notes and sharing them with your doctor will help them learn more about how Brixadi affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before starting Brixadi treatment.

Boxed warning: Risk of serious harm or death if injected into a vein

Brixadi has a boxed warning for the risk of serious harm or death if injected into a vein. A boxed warning is the most serious warning from the FDA. To learn more, see the “Side effects explained” section above.

Other warnings

Brixadi can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether this drug is a good treatment option for you. Talk with your doctor about your health history before starting Brixadi. Be sure to tell them if any of the following factors apply to you:

Alcohol and Brixadi

You should not drink alcohol during treatment with Brixadi. Alcohol can increase your risk of CNS and respiratory depression. These are serious side effects of Brixadi. For more information, see the “Side effects explained” section above.

If you have questions about consuming alcohol during Brixadi treatment, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Brixadi

Before starting Brixadi treatment, it’s important to talk with your doctor if you’re pregnant, breastfeeding, or planning to be either.

Pregnancy

There are risks of receiving Brixadi during pregnancy. For example, your newborn may have neonatal opioid withdrawal symptoms, which can be fatal if not treated. But there are also risks of having untreated opioid use disorder during pregnancy. If you’re pregnant or planning a pregnancy, talk with your doctor before starting Brixadi treatment.

Breastfeeding

Brixadi treatment is generally considered safe while breastfeeding. But if you’re breastfeeding or planning to, you should still talk with your doctor before starting Brixadi. If you breastfeed during treatment, they may recommend that you watch for sleepiness and feeding or breathing problems in your child.

Brixadi contains the active drug buprenorphine, which is an opioid with a risk of misuse. “Misuse” refers to using a drug in a way that’s not prescribed by a doctor.

Misusing Brixadi by injecting it into a vein can cause serious harm or death. The drug has a boxed warning about this risk. A boxed warning is the most serious warning from the FDA. For more information, see the “Side effects explained” section above.

Misusing other opioids during Brixadi treatment can cause serious side effects, particularly CNS and respiratory depression. For more information, see the “Side effects explained” section above.

Like most drugs, Brixadi can cause a number of side effects that range from mild to serious. But most are temporary and go away after a few days to weeks. If you have questions about side effects Brixadi can cause, talk with your doctor. Examples of questions to help get you started include:

  • What pain relievers are safe to take during Brixadi treatment?
  • Will I need any tests to monitor for Brixadi side effects?
  • Do my other treatment options for opioid use disorder have similar side effects?

To learn more about Brixadi, see these articles:

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Disclaimer: Healthline 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.