An Overview of Isentress (Raltegravir)

Brand Name: Isentress
Other Name(s): RAL, raltegravir potassium
Drug Class: Integrase Inhibitors

Isentress pill


Raltegravir can cause serious, life-threatening side effects. These include skin reactions, allergic reactions, and liver problems.

Stop taking raltegravir and contact your health care provider right away if you develop a rash with any of the following symptoms:

  • Fever
  • General ill feeling
  • Extreme tiredness
  • Muscle or joint aches
  • Blisters or sores in your mouth
  • Blisters or peeling of your skin
  • Redness or swelling of your eyes
  • Swelling of your mouth or face
  • Trouble breathing

An allergic reaction to raltegravir can cause liver problems. Contact your health care provider right away if you have any of the following symptoms that could be signs of liver problems:

  • Yellowing of your skin or the whites of your eyes (jaundice)
  • Dark-colored urine
  • Light-colored bowel movements
  • Nausea
  • Vomiting
  • Loss of appetite
  • Pain, aching, or tenderness on the right side of your stomach area

While taking raltegravir, it is important to keep all of your appointments with your health care provider.

What Is Raltegravir?

Raltegravir is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in adults and children. One form of raltegravir, Isentress, is approved for all adults and children weighing at least 4 pounds and 4 ounces (2 kilograms). Another form of raltegravir, Isentress HD, is approved for all adults and children weighing at least 88 pounds (40 kilograms). Raltegravir is always used in combination with other HIV medicines.

Raltegravir belongs to a group of HIV drugs called integrase inhibitors. Integrase inhibitors block an HIV enzyme, a type of protein, called integrase. By blocking integrase, integrase inhibitors prevent HIV from multiplying and can reduce the amount of HIV in the body.

HIV medicines can't cure HIV/AIDS, but taking a combination of HIV medicines (called an HIV treatment regimen) every day helps people with HIV live longer, healthier lives. HIV medicines also reduce the risk of HIV transmission.

What Should I Tell My Health Care Provider Before Taking Raltegravir?

Before taking raltegravir, tell your health care provider:

  • If you are allergic to raltegravir or any other medicines.
  • If you have liver problems.
  • If you have a history of a muscle disorder called rhabdomyolysis or myopathy.
  • If you have increased levels of creatine kinase (an enzyme found mainly in the heart, brain, and skeletal muscle) in your blood.
  • If you have phenylketonuria (PKU). The artificial sweetener in raltegravir chewable tablets (aspartame) contains phenylalanine. Phenylalanine may be harmful to people with PKU.
  • If you are on kidney dialysis treatment.
  • If you have any other medical conditions.
  • If you are pregnant or plan to become pregnant. Whether raltegravir can harm an unborn baby is unknown. Talk to your health care provider about possible risks with taking raltegravir when pregnant.
  • If you are breastfeeding or plan to breastfeed. Do not breastfeed if you have HIV or are taking raltegravir.
  • If you are using hormone-based birth control (such as pills, implants, or vaginal rings). For more information about using birth control and HIV medicines at the same time, view the AIDSinfo HIV and Birth Control infographic.
  • About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Raltegravir may affect the way other medicines or products work, and other medicines or products may affect how raltegravir works. Taking raltegravir together with certain medicines or products may cause serious side effects.

How Should I Take Raltegravir?

Raltegravir comes in the following forms and strengths::

  • 400-mg film-coated tablets (brand name: Isentress).
  • 600-mg film-coated tablets (brand name: Isentress HD).
  • 25-mg and 100-mg chewable tablets (brand name: Isentress).
  • 100-mg single-use packets for oral suspension (brand name: Isentress). An oral suspension is a mixture of a medicine and a liquid that can be taken by mouth.

Take raltegravir according to your health care provider's instructions.

Take raltegravir by mouth, with or without food. Always swallow the film-coated tablets whole. The chewable tablets may be chewed or swallowed whole.

Raltegravir for oral suspension must be mixed with water before use and given within 30 minutes of mixing. Raltegravir for oral suspension comes in a kit that contains the packets of raltegravir and reusable syringes and cups needed to mix and give the medicine. See the detailed instructions that come with the kit for information about the correct way to mix and give a dose of raltegravir for oral suspension. If you have questions about how to mix or give raltegravir for oral suspension, talk to your health care provider or pharmacist.

Do not switch between the film-coated tablets, the chewable tablets, or the oral suspension without talking with your health care provider first.

Always take raltegravir in combination with other HIV medicines.

If you take too much raltegravir, contact your health care provider or local poison control center (1-800-222-1222) right away, or go to the nearest hospital emergency room.

For more information on how to take raltegravir, see the FDA drug label from DailyMed. (DailyMed is a federal website that includes the most recent drug labels submitted to FDA.)

What Should I Do if I Forget a Dose?

If you miss a dose of raltegravir, take the missed dose as soon as you remember it. But if it is almost time for your next dose, skip the missed dose and just take your next dose at the regular time. Do not take two doses at the same time to make up for a missed dose.

What Side Effects Can Raltegravir Cause?

Raltegravir may cause side effects. Many side effects from HIV medicines, such as nausea or occasional dizziness, are manageable. See the AIDS_info_ fact sheet on HIV Medicines and Side Effects for more information.

Some side effects of raltegravir can be serious. Serious side effects of raltegravir include skin reactions, allergic reactions, and liver problems. (See the WARNING box above.)

Other possible side effects of raltegravir include:

  • Changes in your immune system (called immune reconstitution inflammatory syndrome or IRIS). IRIS is a condition that sometimes occurs when the immune system begins to recover after treatment with an HIV medicine. As the immune system gets stronger, it may have an increased response to a previously hidden infection.
  • Unexplained muscle pain, tenderness, or weakness. This may be a sign of a rare but serious muscle problem that can lead to kidney problems.

Tell your health care provider if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of raltegravir. To learn more about possible side effects of raltegravir, read the drug label or package insert or talk to your health care provider or pharmacist.

You can report side effects to FDA at 1-800-FDA-1088 (1-800-332-1088) or online.

How Should Raltegravir Be Stored?

  • Store raltegravir at room temperature, 68°F to 77°F (20°C to 25°C).
  • Do not use raltegravir if the original seal over the container opening is broken or missing.
  • Keep raltegravir film-coated and chewable tablets in the container that they came in and keep the container tightly closed. If the container has a small packet of drying agent (called a desiccant), do not remove it. The desiccant protects the medicine from moisture.
  • Keep raltegravir for oral suspension in the container that it came in. Do not open the foil packet until ready for use.
  • Throw away raltegravir that is no longer needed or expired (out of date). Follow FDA guidelines on how to safely dispose of unused medicine.
  • Keep raltegravir and all medicines out of reach of children.

Where Can I Find More Information About Raltegravir?

More information about raltegravir is available:

Manufacturer Information

Merck & Co., Inc.
Main number: 908-423-1000
Patient assistance: 800-727-5400

The above Patient Version drug summary is based on the following FDA label(s): Tablet (chewable), tablet (film coated), granule for oral suspension.

[Note from This article was created by AIDSinfo, who last updated it on Aug. 1, 2018. We have cross-posted it with their permission.]