Drug Database: Fosamprenavir

What is fosamprenavir?What is fosamprenavir?

What is fosamprenavir?

Fosamprenavir (brand name: Lexiva) is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in adults and children. Fosamprenavir is always used in combination with other HIV medicines.

Although fosamprenavir is FDA-approved for use in adults and children, it is no longer commonly used or recommended as an HIV treatment. The Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents with HIV and the Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection no longer contain detailed or updated information on the use of fosamprenavir. Please refer to the FDA drug label for additional information regarding the use of fosamprenavir in people with HIV.

HIV medicines cannot cure HIV/AIDS, but taking HIV medicines 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, do not 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 fosamprenavir?What should I tell my health care provider before taking fosamprenavir?

What should I tell my health care provider before taking fosamprenavir?

Before taking fosamprenavir, tell your health care provider:

• If you are allergic to fosamprenavir, amprenavir, sulfonamides (sulfa medicines), or any other medicines.
• If you have ever had liver problems, including hepatitis B virus infection (HBV) or hepatitis C virus infection (HCV).
• If you have kidney problems.
• If you have diabetes or high blood sugar (hyperglycemia).
• If you have hemophilia.
• If you have high triglycerides or cholesterol.
• If you have any other medical conditions.
• If you are pregnant or plan to become pregnant. Talk to your health care provider about the risks and benefits of taking fosamprenavir during pregnancy. For more information on the use of fosamprenavir during pregnancy, please refer to the Recommendations for the Use of Antiretroviral Drugs During Pregnancy and Interventions to Reduce Perinatal HIV Transmission in the United States.
• If you are breast/chestfeeding or plan to breast/chestfeed. For people with HIV in the United States, the Guideline recommends speaking with your health care provider to discuss options for feeding your baby. People with suppressed viral load have a less than 1% chance of transmitting HIV to their baby via their own milk.
• If you are using hormone-based birth control (such as pills, implants, or vaginal rings). Fosamprenavir 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 fosamprenavir. For more information about using birth control and HIV medicines at the same time, view the HIVinfo HIV and Birth Control infographic.
• About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products (including St. John’s wort) you are taking or plan to take. Fosamprenavir may affect the way other medicines or products work, and other medicines or products may affect how fosamprenavir works. Taking fosamprenavir together with certain medicines or products may cause serious, life-threatening side effects.

How should I take fosamprenavir?How should I take fosamprenavir?

How should I take fosamprenavir?

Fosamprenavir comes as 700-mg tablets.

Take fosamprenavir according to your health care provider’s instructions. Do not miss a dose of fosamprenavir, and do not change your dose or stop taking fosamprenavir without first talking with your health care provider.

Take fosamprenavir tablets by mouth with or without food.

If you are taking antacids or H2 blockers (medicines for reducing stomach acid), check with your health care provider to find out if you can take these medicines with fosamprenavir. If your health care provider tells you to continue taking antacids or H2 blockers, carefully follow instructions on how to take them with fosamprenavir.

Always take fosamprenavir in combination with other HIV medicines.

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

For more information on how to take fosamprenavir, see the FDA drug label.

What should I do if I forget a dose?What should I do if I forget a dose?

What should I do if I forget a dose?

If you miss a dose of fosamprenavir, 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 fosamprenavir cause?What side effects can fosamprenavir cause?

What side effects can fosamprenavir cause?

Fosamprenavir may cause side effects. Some side effects of fosamprenavir can be serious as noted above. Many side effects from HIV medicines, such as nausea or occasional dizziness, are manageable. See the HIVinfo fact sheet on HIV Medicines and Side Effects for more information.

Other possible side effects of fosamprenavir include:

• Diabetes and high blood sugar (hyperglycemia).
• 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.
• Increase in body fat (seen in some people taking protease inhibitors).
• Changes in blood test results. These include increases in liver function tests, blood fat levels (cholesterol and triglycerides), and decreases in red blood cells.
• Increased bleeding in some people with hemophilia.
• Kidney stones. Contact your health care provider right away if you have pain in your side, blood in your urine, or pain when you urinate.

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 fosamprenavir. To learn more about possible side effects of fosamprenavir, 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 fosamprenavir be stored?How should fosamprenavir be stored?

How should fosamprenavir be stored?

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

Where can I find more information about fosamprenavir?Where can I find more information about fosamprenavir?

Where can I find more information about fosamprenavir?

• For more information on the use of fosamprenavir in people with HIV, please refer to the Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents with HIV and the Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection.
• This Patient Version drug summary is based on the following FDA label(s): Tablet (film coated). The Patient Information section of the label includes information for people taking fosamprenavir.
• The American Hospital Formulary Service (AHFS) Patient Medication Information for fosamprenavir available from MedlinePlus.
• Fosamprenavir-related research studies, from ClinicalTrials.gov. The ClinicalTrials.gov search can be modified so that you can get results that better match your interests.)
• A list of FDA-approved HIV medicines, from HIVinfo.