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An Overview of Isentress (Raltegravir, MK-0518)

August 23, 2013



Brand Name: Isentress
Other Name(s): RAL, raltegravir potassium
Drug Class: Integrase Inhibitors
Approved Use: Treatment of HIV Infection


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.
  • Problems breathing.

An allergic reaction to raltegravir can cause liver problems. Call your health care provider right away if you have any of the following symptoms that may signal liver problems:

  • Yellowing of your skin or 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 below your ribs.

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 2 years of age and older. Raltegravir is always used in combination with other anti-HIV medicines.

Raltegravir is a type of anti-HIV medicine called an integrase inhibitor. Raltegravir works by blocking integrase, an HIV enzyme. This prevents HIV from replicating and lowers the amount of HIV in the blood.

Raltegravir does not cure HIV/AIDS. It is not known if raltegravir reduces the risk of passing HIV to other people.

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 phenylketonuria (PKU). Raltegravir chewable tablets contain phenylalanine as part of the artificial sweetener aspartame. The artificial sweetener may be harmful to people with PKU.
  • If you have any other medical problems.
  • If you are pregnant or plan to become pregnant. Whether raltegravir can harm an unborn baby is unknown.
  • If you are breastfeeding or plan to breastfeed. Do not breastfeed if you are infected with HIV or are taking raltegravir.
  • 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).
  • 25-mg and 100-mg chewable tablets (brand name: Isentress).

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. Do not change your dose of raltegravir or switch between the film-coated tablet and the chewable tablet without talking with your health care provider first.

Always take raltegravir in combination with other anti-HIV medicines.

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

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

What should I do if I forget a dose?

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 can cause serious, life-threatening side effects. These include skin reactions, allergic reactions, and liver problems. (See the WARNING above.)

Other possible side effects of raltegravir include:

  • Changes in the immune system (immune reconstitution inflammatory syndrome).
  • Raltegravir chewable tablets contain phenylalanine as part of the artificial sweetener aspartame. The artificial sweetener may be harmful to people with phenylketonuria (PKU).
  • 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. Ask your health care provider or pharmacist for more information on possible side effects of raltegravir.

How should raltegravir be stored?

  • Store raltegravir at room temperature, 68°F to 77°F (20°C to 25°C).
  • Store raltegravir chewable tablets in the original package, with the bottle tightly closed. Keep the drying agent (desiccant) in the bottle to protect the tablets from moisture.
  • Safely throw away raltegravir that is no longer needed or expired (out of date).
  • Keep raltegravir and all medicines out of reach of children.

Where can I find more information about raltegravir?

More information about raltegravir, is available:

  • The raltegravir drug label, from DailyMed. The Patient Counseling Information section of the label includes information for people taking raltegravir.
  • Raltegravir-related research studies, from the AIDSinfo database of study summaries.
  • A list of FDA-approved generics for anti-HIV medicines, from FDA.

Manufacturer Information


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This article was provided by AIDSinfo. Visit the AIDSinfo website to find out more about their activities and publications.
See Also
More on HIV Medications
More on Isentress (Raltegravir)