Fosamprenavir

Fosamprenavir is a prescription medication to treat human immunodeficiency virus (HIV) infection. Fosamprenavir belongs to a group of drugs called protease inhibitors. It works by decreasing the amount of HIV in the blood.

This medication comes in tablet and liquid forms and is usually taken twice daily, with or without food.

Common side effects include nausea, vomiting, and diarrhea.

Fosamprenavir is a prescription medicine used to treat HIV infection. HIV is the virus that causes AIDS (acquired immune deficiency syndrome). Fosamprenavir is always used with other anti-HIV medicines.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

• fosamprenavir 1400 mg twice daily (without Norvir)
• fosamprenavir 1400 mg once daily and Norvir 200 mg once daily
• fosamprenavir 1400 mg once daily and Norvir 100 mg once daily
• fosamprenavir 700 mg twice daily and Norvir 100 mg twice daily. 

Fosamprenavir may cause the following side effects:

• skin rash. Skin rashes, some with itching, have happened in patients taking fosamprenavir. Swelling of the face, lips, and tongue (angioedema) has also been reported. Tell your healthcare provider if you get a rash or develop facial swelling after starting fosamprenavir.
• diabetes and high blood sugar (hyperglycemia). Some patients had diabetes before taking fosamprenavir while others did not. Some patients may need changes in their diabetes medicine. Others may need a new diabetes medicine.
• increased bleeding problems in some patients with hemophilia.
• worse liver disease. Patients with liver problems, including hepatitis B or C, are more likely to get worse liver disease when they take anti-HIV medicines like fosamprenavir.
• changes in blood tests. Some people have changes in blood tests while taking fosamprenavir. These include increases seen in liver function tests and blood fat levels, and decreases in white blood cells. Your healthcare provider may do regular blood tests to see if fosamprenavir is affecting your body.
• changes in body fat. These changes have happened in patients taking antiretroviral medicines like fosamprenavir. The changes may include an increased amount of fat in the upper back and neck ("buffalo hump"), breast, and around the trunk. Loss of fat from the legs, arms, and face may also happen. The cause and long-term health effects of these conditions are not known at this time.
• kidney stones have been reported in some patients taking fosamprenavir. If you develop signs or symptoms of kidney stones (pain in your side, blood in your urine, pain when you urinate) tell your healthcare provider right away.

Do not take fosamprenavir if you:

• are allergic to fosamprenavir or any of its ingredients. 
• are allergic to Agenerase (amprenavir).

Avoid doing things that can spread HIV infection since fosamprenavir doesn't stop you from passing the HIV infection to others.

• Do not share needles or other injection equipment.
• Do not share personal items that can have blood or body fluids on them, like toothbrushes or razor blades.
• Do not have any kind of sex without protection. Always practice safer sex by using a latex or polyurethane condom to lower the chance of sexual contact with semen, vaginal secretions, or blood.

Serious side effects have been reported. See "Drug Precautions" section.

Common side effects of fosamprenavir are nausea, vomiting, and diarrhea. Tell your healthcare provider about any side effects that bother you or that won't go away.

This list of side effects of fosamprenavir is not complete. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Fosamprenavir can cause dangerous and life-threatening interactions if taken with certain other medicines. Tell your healthcare provider about all the medicines you take, including prescription and nonprescription medicines, vitamins, and herbal supplements.

Do not take the following medicines with fosamprenavir:

• Halcion (triazolam; used for insomnia)
• Ergot medicines: dihydroergotamine, ergonovine, ergotamine, and methylergonovine such as Cafergot, Migranal, D.H.E. 45, ergotrate maleate, Methergine, and others (used for migraine headaches)
• Propulsid (cisapride), used for certain stomach problems
• Versed (midazolam), used for sedation
• Orap (pimozide), used for Tourette’s disorder
• Revatio (sildenafil), used for treatment of pulmonary arterial hypertension
• Uroxatral (alfuzosin), used for benign prostatic hyperplasia (BPH)

You should not take Agenerase (amprenavir) and fosamprenavir at the same time.

There are other medicines you should not take if you are taking fosamprenavir and Norvir (ritonavir) together. You could develop serious or life-threatening problems. Tell your healthcare provider about all medicines you are taking before you begin taking fosamprenavir and Norvir (ritonavir) together.

Women who use birth control pills should choose a different kind of contraception. The use of fosamprenavir with Norvir (ritonavir) in combination with birth control pills may be harmful to your liver. The use of fosamprenavir with or without Norvir may decrease the effectiveness of birth control pills. Talk to your healthcare provider about choosing an effective contraceptive.

Tell your healthcare provider if you are pregnant or planning to become pregnant. It is not known if fosamprenavir can harm your unborn baby. You and your healthcare provider will need to decide if fosamprenavir is right for you. If you use fosamprenavir while you are pregnant, talk to your healthcare provider about how you can be on the Antiretroviral Pregnancy Registry.

Women who use birth control pills should choose a different kind of contraception. The use of fosamprenavir with NORVIR (ritonavir) in combination with birth control pills may be harmful to your liver. The use of fosamprenavir with or without NORVIR may decrease the effectiveness of birth control pills. Talk to your healthcare provider about choosing an effective contraceptive.

Tell your healthcare provider if you are breastfeeding. You should not breastfeed if you are HIV-positive because of the chance of passing the HIV virus to your baby through your milk. Also, it is not known if fosamprenavir can pass into your breast milk and if it can harm your baby. If you are a woman who has or will have a baby, talk with your healthcare provider about the best way to feed your baby.

Women who use birth control pills should choose a different kind of contraception. Talk to your healthcare provider about choosing an effective contraceptive.

• The use of fosamprenavir with Norvir (ritonavir) in combination with birth control pills may be harmful to your liver.
• The use of fosamprenavir with or without Norvir may decrease the effectiveness of birth control pills.

Fosamprenavir can cause changes in body fat. The changes may include an increased amount of fat in the upper back and neck ("buffalo hump"), breast, and around the trunk. Loss of fat from the legs, arms, and face may also happen.

When your supply of fosamprenavir or other anti-HIV medicine starts to run low, get more from your healthcare provider or pharmacy. The amount of HIV virus in your blood may increase if one or more of the medicines are stopped, even for a short time.