Apretude (cabotegravir extended-release injectable suspension) is a prescription drug used to help prevent HIV. Apretude can cause side effects that range from mild to serious. Examples include injection site pain and liver damage.

Specifically, Apretude is approved to help prevent HIV in at-risk adults and adolescents weighing at least 35 kilograms (kg). (For reference, 1 kg is about 2.2 pounds [lb]. This means individuals must weigh at least 77 lb.) They also must meet certain other criteria.

The active ingredient in Apretude is cabotegravir. It’s an extended-release suspension that a healthcare professional gives by injection. The form is long-acting, which means it stays in the body and maintains its effect for a long time.

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

Apretude has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effects explained” section below.

Some people may experience mild to serious side effects during their Apretude therapy. Examples of the drug’s commonly reported side effects include:

  • diarrhea
  • fatigue (low energy)
  • fever
  • headache
  • injection site reaction (Learn more about this in the “Side effects explained” section below.)

The following sections include more side effects of Apretude. Each person’s experience with side effects may differ.

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

  • belly pain
  • diarrhea
  • dizziness
  • fatigue (low energy)
  • fever
  • gas
  • headache
  • injection site reaction (Learn more about this in the “Side effects explained” section below.)
  • nausea
  • sleep problems, such as trouble sleeping or unusual dreams

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

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

Allergic reaction

For some people, Apretude can cause an allergic reaction. Allergic reaction has been reported by people using Apretude as part of a treatment plan with other medications. But it’s not known whether the allergic reaction was caused by Apretude or a different medication.

In general, symptoms of allergic reaction can be mild or serious.

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 and can determine whether you should keep using Apretude.

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

Your doctor can confirm whether you’ve had a serious allergic reaction to Apretude. If they do, they may have you switch to a different therapy.

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

To learn more about liver damage and risk of drug resistance in people with undiagnosed HIV, see the “Side effects explained” section below.

If you develop serious side effects while using Apretude, 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 call your local emergency number.

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 Apretude, visit MedWatch.

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you are not in the same household, stay on the phone with them until help arrives.

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

Is weight gain a side effect of Apretude?

Yes, weight gain is a possible side effect of Apretude. In studies, weight gain was a rare side effect reported in people using Apretude. Weight gain reported with Apretude ranged from about 2.5 lb to about 9 lb. No information is available about how long the weight gain lasted. Also, no information indicates whether people were able to lose the extra weight.

If you experience weight gain while using Apretude, tell your doctor. They can determine the most likely cause and suggest ways to manage it, if needed.

Can Apretude cause long-term side effects?

It’s possible. Long-term side effects include those that may start at any time you’re using a drug. These can occur even if you’ve used it for a long time. It also includes side effects that may not go away, even after you stop using the drug.

Apretude is a long-acting injection, so the drug can stay in your body for long periods of time. After your last injection, small amounts can be present in your body for a year or longer. This means side effects may take a long time to go away, even if they become serious or bothersome.

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

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

Injection site reaction

Injection site reaction was the most common side effect reported in studies of Apretude. Injection site reaction includes the following symptoms where Apretude is injected:

  • bruising, redness, or discoloration of the skin
  • hardness of the skin
  • lump under the skin
  • pain
  • swelling
  • warmth

Most often, injection site reaction lasts only a few days. It also tends to become less common and less severe with each injection.

Some factors can increase the risk of injection site reaction when using this drug. These include the following:

  • You’ve had a reaction to another drug in the same class of drugs as Apretude: Because of this, you may have a higher chance of injection site reaction with Apretude.
  • The medication is too cold: Receiving an injection of Apretude that hasn’t reached room temperature can increase your chance of injection site reaction.
  • Injection sites are not rotated: Apretude injections are given only in the buttock muscle. Over time, this may cause irritation at the injection site.

What might help

If you have an injection site reaction after an Apretude injection, tell your doctor. They’ll be able to recommend ways to help ease your symptoms. They may suggest applying a warm or cold compress to the area or taking over-the-counter medications.

Liver damage

Liver damage was a rare side effect reported in studies of Apretude. Liver damage may cause symptoms such as:

Liver damage has occurred in people who have had liver problems in the past and those who have not.

What might help

Due to this risk, your doctor may check your liver function with lab tests from time to time.

If you have symptoms of liver damage during Apretude therapy, tell your doctor right away. They’ll likely recommend stopping Apretude.

Risk of drug resistance in people with undiagnosed HIV

Apretude has a boxed warning for the risk of drug resistance in people with undiagnosed HIV. A boxed warning is the most serious warning from the FDA.

Preexposure prophylaxis (PrEP) helps prevent HIV. Apretude is a PrEP therapy. In people with undiagnosed HIV who use Apretude, drug resistance can develop. Due to this risk, your doctor must test you for HIV before starting Apretude and before each injection. You’ll be able to receive an injection only if your test for HIV is negative.

If you develop symptoms of HIV while using Apretude, tell your doctor right away. Symptoms may include:

What might help

Due to the risk of drug resistance, you should use Apretude only if you have a negative HIV test.

If you have a positive HIV test before starting Apretude, your doctor may recommend HIV treatment instead of Apretude for PrEP. If you have a positive HIV test or develop symptoms of HIV during Apretude therapy, your doctor will likely stop giving you Apretude. And they’ll likely recommend HIV treatment instead.

Keeping track of side effects

During your Apretude therapy, 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 a new drug or combination of treatments or therapies.

Your side effect notes can include things such as:

  • 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

Sharing these notes with your doctor will help them learn more about how Apretude affects you. They can then use this information to adjust your therapy plan if needed.

Below is important information you should consider before starting Apretude.

Boxed warning: Risk of drug resistance in people with undiagnosed HIV

Apretude has a boxed warning. A boxed warning is the most serious warning from the FDA. For details, see the “Side effects explained” section above.

Other warnings

Apretude can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors also may affect whether Apretude is a good option for you.

Talk with your doctor about your health history before you start Apretude. Be sure to tell them if any of the following factors apply to you:

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.