An Overview of Invirase (Saquinavir)

Brand Name: Invirase
Other Names: SQV, saquinavir mesylate
Drug Class: Protease Inhibitors

Invirase pill


Saquinavir can cause serious, life-threatening side effects. These include heart rhythm problems and worsening liver problems in people with pre-existing liver problems or a history of alcoholism.

Contact your health care provider right away if you have any of the following symptoms that could be signs of heart rhythm problems:

  • Dizziness
  • Lightheadedness
  • Fainting
  • Sensation of abnormal heartbeats

Contact your health care provider right away if you have any of the following symptoms that could be signs of liver problems:

  • Loss of appetite
  • Yellowing of your skin or the whites of your eyes (jaundice)
  • Dark-colored urine
  • Pale-colored bowel movements
  • Itchy skin
  • Pain in the stomach area (abdominal pain)

Taking saquinavir together with certain medicines can cause serious and/or life-threatening side effects.

Do not take saquinavir if you are taking cobicistat (brand name: Tybost).

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

What Is Saquinavir?

Saquinavir is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in people over 16 years of age. Saquinavir is always used in combination with the HIV medicine ritonavir (brand name: Norvir) and other HIV medicines.

Saquinavir belongs to a class (group) of HIV drugs called protease inhibitors (PIs). PIs block an HIV enzyme called protease. (An enzyme is a protein that starts or increases the speed of a chemical reaction.) By blocking protease, PIs 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 regimen) every day helps people with HIV live longer, healthier lives. HIV medicines also reduce the risk of HIV transmission. If you are taking HIV medicines, including saquinavir, don't cut down on, skip, or stop taking them unless your health care provider tells you to.

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

Before taking saquinavir, tell your health care provider:

  • If you are allergic to saquinavir or any other medicines.
  • If you have any heart problems, including if you are at risk of or have a complete atrioventricular heart block or have a condition called congenital long QT syndrome.
  • If you have low levels of potassium or magnesium in your blood.
  • If you have diabetes.
  • If you have liver problems, including hepatitis B virus (HBV) or hepatitis C virus (HCV) infection.
  • If you have a history of alcoholism.
  • If you have hemophilia.
  • If you have any other medical conditions.
  • If you are pregnant or plan to become pregnant. Whether saquinavir can harm an unborn baby is unknown. Saquinavir should be used during pregnancy only if the potential benefits outweigh the risks. Talk to your health care provider about possible risks with taking saquinavir when pregnant.
  • If you are breastfeeding or plan to breastfeed. Do not breastfeed if you have HIV or are taking saquinavir.
  • If you are using hormone-based birth control (such as pills, implants, or vaginal rings). Saquinavir may make these forms of birth control less effective. Your health care provider can help you decide how to adjust your birth control while you are taking saquinavir. 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 (particularly St. John's Wort) you are taking or plan to take. Saquinavir may affect the way other medicines or products work, and other medicines or products may affect how saquinavir works. Taking saquinavir together with certain medicines or products may cause serious, life-threatening side effects.

How Should I Take Saquinavir?

Saquinavir (brand name: Invirase) comes in the following forms and strengths:

  • 200-mg hard-gel capsules
  • 500-mg film-coated tablets

(A 200-mg soft-gel capsule form of saquinavir was formerly sold under the brand name Fortovase. Sale of Fortovase was discontinued in February 2006.)

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

Take saquinavir at the same time that you take the HIV medicine ritonavir (brand name: Norvir). Take saquinavir, along with ritonavir, within 2 hours after a full meal.

Always take saquinavir in combination with other HIV medicines.

If you are unable to swallow saquinavir capsules whole, open the capsules and mix the contents with 3 teaspoons (15 mL) of sugar syrup or jam. People with type 1 diabetes or glucose intolerance should use sorbitol syrup.

If you take too much saquinavir, 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 saquinavir, 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 saquinavir, 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 Saquinavir Cause?

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

Some side effects of saquinavir can be serious. Serious side effects of saquinavir include heart rhythm problems and worsening liver problems in people with pre-existing liver problems or a history of alcoholism. (See the WARNING box above.)

Other possible side effects of saquinavir include:

  • Diabetes and high blood sugar (hyperglycemia).
  • Changes in body fat (including gain or loss of fat).
  • 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.
  • Increases in certain fat (cholesterol and triglyceride) levels in the blood (hyperlipidemia).
  • Increased bleeding in people with hemophilia.

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 saquinavir. To learn more about possible side effects of saquinavir, 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 at

How Should Saquinavir Be Stored?

  • Store saquinavir at room temperature, 68°F to 77°F (20°C to 25°C).
  • Keep saquinavir in a tightly closed container.
  • Do not use saquinavir if the original seal over the container opening is broken or missing.
  • Throw away saquinavir that is no longer needed or expired (out of date). Follow FDA guidelines on how to safely dispose of unused medicine.
  • Keep saquinavir and all medicines out of reach of children.

Where Can I Find More Information About Saquinavir?

More information about saquinavir is available:

Manufacturer Information

Hoffman-La Roche
Main line: 888-835-2555

The above Patient Version drug summary is based on the following FDA label(s): Capsule, tablet (film coated).

[Note from TheBody: This article was created by AIDSinfo, who last updated it on Apr. 30, 2018. We have cross-posted it with their permission.]