In the U.S.—

In Canada—

• Antiviral

Amprenavir (Am-PREN-a-veer ) is a protease inhibitor. It is used in combination with other medicines to treat patients who are infected with the human immunodeficiency virus (HIV).

HIV is the virus that causes acquired immune deficiency syndrome (AIDS). Amprenavir may slow down the destruction of the immune system caused by HIV. This may help delay the development of problems usually related to AIDS or HIV disease. However, this medicine will not cure or prevent HIV infection, and it will not keep you from spreading the virus to other people. Patients who are taking this medicine may continue to have the problems usually related to AIDS or HIV disease.

This medicine is available only with your doctor's prescription, in the following dosage forms:

Oral
• Capsules (U.S. and Canada)
• Oral solution (U.S. and Canada)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For amprenavir, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to amprenavir or sulfa medicines. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Amprenavir has not been studied in pregnant women. However, studies in animals have shown that amprenavir causes birth defects and other problems. Amprenavir capsules should only be used during pregnancy if the benefit outweighs the potential risk. Amprenavir oral solution should only be used during pregnancy if the benefit outweighs the potential risk. Before taking this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding—It is not known whether amprenavir passes into breast milk. However, breast-feeding is not recommended in patients with HIV-infection because of the risk of passing the HIV virus on to the nursing infant. Mothers should not breast-feed while taking amprenavir.

Children—This medicine has been tested in children 4 years of age and older. In effective doses, the medicine has not been shown to cause different side effects or problems than it does in adults.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. However, specific side effects may be especially likely to occur in elderly patients, who are usually more sensitive than younger adults to the effects of amprenavir. There is no specific information comparing use of amprenavir in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking amprenavir, it is especially important that your health care professional know if you are taking any other medicines (prescription or over-the-counter [OTC], especially the following:

• Alcohol—the ingredients in amprenavir oral solution should not be mixed with alcohol. Do not use together.

• Amiodarone or
• Lidocaine (systemic) or
• Quinidine or
• Tricyclic antidepressants (amitriptyline [e.g., Elavil], amoxapine [e.g., Asendin], clomipramine [e.g., Anafranil], desipramine [e.g., Norpramin], doxepin [e.g., Sinequan], imipramine [e.g., Tofranil], nortriptyline [e.g., Aventyl, Pamelor], protriptyline [e.g., Vivactil], trimipramine [e.g., Surmontil]—There is a possibility that amprenavir may interfere with the removal of these medicines from the body, which could lead to serious side effects

• Antacids or
• Didanosine (e.g., Videx)—Use of antacids or didanosine with amprenavir may keep amprenavir from working properly if taken close together. Antacids and didanosine should be taken at least one hour before or after amprenavir.

• Bepridil (e.g. Vascor)—Use of bepridil and amprenavir together can cause life-threatening reactions. Use together with caution.

• Carbamazepine (e.g., Tegretol) or
• Phenobarbital or
• Phenytoin (e.g., Dilantin)—Use of these medicines with amprenavir may cause amprenavir to be less effective. Use with caution.

• Cyclosporine (e.g., Sandimmune) or
• Rapamycin (e.g., Rapamune) or
• Tacrolimus (e.g., Prograf)—Use with amprenavir may cause more side effects

• Cisapride (e.g., Propulsid)—Do not use with amprenavir as life-threatening reactions can occur.

• Delavirdine (e.g., Rescriptor)—Use with amprenavir may lead to a possible resistance to delavirdine. They should not be administered together.

• Disulfiram (e.g., Antabuse) or
• Metronidazole (e.g., Flagyl)—Use of these medicines with amprenavir oral solution can be dangerous. Do not use together.

• Ergot derivatives (e.g., D.H.E., Methergine, Ergotrate)—Use of these medicines with amprenavir can cause serious side effects. Do not use together.

• Itraconazole (e.g., Sporanox) or
• Ketoconazole (e.g., Nizoral)—The dose of these medicines may need to be lowered.

• HMG-CoA reductase inhibitors (atorvastatin [e.g., Lipitor], lovastatin [e.g., Mevacor], simvastatin [e.g., Zocor]—Use of amprenavir may cause a high blood level of these medicines. If you are on atorvastatin while on amprenavir, use the lowest possible dose or consider using other HMG-CoA reductase inhibitors.

• Midazolam (e.g., Versed) or
• Triazolam (e.g., Halcion)—Use of these medicines with amprenavir can cause serious reactions and should not be used together.

• Oral contraceptives—Use of these medicines may cause amprenavir to be less effective. Alternate methods of birth control are recommended.

• Pimozide (e.g., Orap)—Use of this medicine with amprenavir can cause serious reactions. Do not use together.

• Rifabutin (e.g., Mycobutin)—Use of amprenavir can cause increased blood levels of rifabutin. Rifabutin can cause decreased blood levels of amprenavir.

• Rifampin—Use of this medicine may lead to possible resistance to amprenavir. Do not use together.

• Ritonavir capsules (e.g., Norvir)—Using this medicine with amprenavir can cause an increase in the amount of amprenavir your body gets.

• Ritonavir oral solution—Amprenavir and ritonavir oral solution may remain in your body for longer periods of time. Use of these medicines together is not recommended.

• Saquinavir (e.g., Forovase, Invirase)—Amprenavir levels may be decreased.

• Sildenafil (e.g., Viagra)—Use of this medicine with amprenavir may increase the amount of sildenafil in the body and may increase the chance for side effects, such as low blood pressure, changes in vision, and erection of the penis lasting more than 4 hours. Use a reduced dose of sildenafil.

• St. John's wort—This medicine can decrease the blood levels of amprenavir in your body. It may also result in resistance to amprenavir.

• Warfarin (e.g., Coumadin)—Amprenavir may decrease your blood clotting time and make you bleed more easily.

• Diabetes mellitus or
• Hemophilia—Amprenavir may make these conditions worse

• Kidney failure or
• Liver failure—Amprenavir oral solution should not be used because serious side effects may occur

• Liver disease—Effects of amprenavir may be increased because of slower removal of amprenavir from the body

• Vitamin K deficiency—The high amounts of vitamin E in amprenavir dosage forms may increase the chance of bleeding problems in patients who are deficient in vitamin K

Amprenavir may be taken with or without food. However, it should not be taken with a high-fat meal. Taking amprenavir with a high-fat meal may decrease the amount of amprenavir that is absorbed by the body and prevent the medicine from working properly.

You should not drink alcoholic beverages while you are taking the oral solution form of this medicine.

It is important to take amprenavir as part of a combination treatment. Your dose of medicine will be based on what other medicines you are taking, as well as your weight. Be sure to take all the medicines your doctor has prescribed for you, including amprenavir.

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. Also, do not stop taking this medicine without checking with your doctor first.

Keep taking amprenavir for the full time of treatment, even if you begin to feel better.

This medicine works best when there is a constant amount in the blood. To help keep the amount constant, do not miss any doses. Also, it is best to take the doses at evenly spaced times, day and night. For example, if you are to take two doses a day, the doses should be spaced about 12 hours apart. If you need help in planning the best times to take your medicine, check with your health care professional.

Only take medicine that your doctor has prescribed especially for you. Do not share your medicine with others.

Dosing—

The dose of amprenavir will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of amprenavir. If your dose is different, do not change it unless your doctor tells you to do so.

The number of capsules or teaspoonfuls of solution that you take depends on the strength of the medicine.

• For oral dosage form (capsules):
  • For treatment of HIV infection:
    • Adults, adolescents 17 years of age and older, and adolescents 13 through 16 years of age who weigh 50 kilograms (kg) (110 pounds) or more—1200 milligrams (mg) (eight 150-mg capsules) two times a day.
    • Children 4 to 13 years of age and adolescents 13 through 16 years of age who weigh less than 50 kg (110 pounds)—Dose is based on body weight and must be determined by your doctor. The usual dose is 20 mg per kg (9.1 mg per pound) of body weight two times a day or 15 mg per kg (6.8 mg per pound) of body weight three times a day, up to a maximum dose of 2400 mg per day.
    • Children up to 4 years of age—Use and dose must be determined by your doctor.
• For oral dosage form (oral solution):
  • For treatment of HIV infection:
    • Adults, adolescents 17 years of age and older, and adolescents 13 through 16 years of age who weigh 50 kg (110 pounds) or more— 1400 mg two times a day.
    • Children 4 to 12 years of age and adolescents 13 through 16 years of age who weigh less that 50 kg (110 pounds)—Dose is based on body weight and must be determined by your doctor. The usual dose is 22.5 mg per kg (10.2 mg per pound) of body weight two times a day or 17 mg per kg (7.7 mg per pound) of body weight three times a day, up to a maximum dose of 2800 mg per day.
    • Children up to 4 years of age—Use and dose must be determined by your doctor.

Missed dose—

If you are taking amprenavir capsules and you miss a dose , take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

If you are taking amprenavir oral solution and you miss a dose, if it has been less than 4 hours since the dose was missed, take it immediately and then go back to your regular dosing schedule. If it has been more than 4 hours since the dose was missed, skip it and go back to your regular dosing schedule.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Keep the medicine from freezing. Do not refrigerate.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Do not take any other medicines without checking with your doctor first. This includes prescription and nonprescription medicines. This also includes food supplements, herbs and vitamins. To do so may increase the chance of side effects from amprenavir or other medicines.

This medicine may decrease the effects of some oral contraceptives (birth control pills). To avoid unwanted pregnancy, it is a good idea to use some additional contraceptive measures while being treated with amprenavir.

For patients with diabetes: Amprenavir may affect blood sugar levels. If you notice a change in the results of your blood or urine sugar tests or if you have any questions, check with your doctor.

Do not take vitamin E supplements while you are taking amprenavir. At recommended dosages, amprenavir supplies more than the Reference Daily Intake of vitamin E for adults and children.

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly and to check for unwanted effects, especially increases in blood sugar.

Amprenavir does not decrease the risk of transmitting the HIV infection to others through sexual contact or by contamination through blood. HIV may be acquired from or spread to others through infected body fluids, including blood, vaginal fluid, or semen. If you are infected, it is best to avoid any sexual activity involving an exchange of body fluids with other people. If you do have sex, always wear (or have your partner wear) a condom (“rubber”). Only use condoms made of latex, and use them every time you have vaginal, anal, or oral sex. The use of a spermicide (such as nonoxynol-9) may also help prevent the spread of HIV if it is not irritating to the vagina, rectum, or mouth. Spermicides have been shown to kill HIV in lab tests. Do not use oil-based jelly, cold cream, baby oil, or shortening as a lubricant—these products can cause the condom to break. Lubricants without oil, such as K-Y Jelly, are recommended. Women may wish to carry their own condoms. Birth control pills and diaphragms will help protect against pregnancy, but they will not prevent someone from giving or getting the AIDS virus. If you inject drugs, get help to stop. Do not share needles or equipment with anyone. In some cities, more than half of the drug users are infected, and sharing even 1 needle or syringe can spread the virus. If you have any questions about this, check with your health care professional.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• More common
  • Burning or prickling sensation in arms or legs;  dry or itchy skin;  fatigue;  increased cholesterol and triglycerides;  increased hunger;  increased thirst;  increased urination;  skin rash 
  
  

• Less common
  • depression;  mood or mental changes 
  
  

• Rare
  • Blistering, peeling, or loosening of skin and mucous membranes ;  buffalo hump;  fever;  general feeling of discomfort or illness;  unexplained weight loss 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Abdominal pain;  burning or prickling sensation around the mouth;  diarrhea;  headache;  nausea;  vomiting 
  
  

• Less common or rare
  • Change in sense of taste;  unusual tiredness or weakness 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

It is possible that the fat on your body may distribute itself differently or you may accumulate more body fat while you are taking this medicine. If you have concerns about this, check with your doctor.