- What is amprenavir, and how does it work (mechanism of action)?
- What brand names are available for amprenavir?
- Is amprenavir available as a generic drug?
- Do I need a prescription for amprenavir?
- What are the side effects of amprenavir?
- What is the dosage for amprenavir?
- Is amprenavir safe to take if I'm pregnant or breastfeeding?
- What else should I know about amprenavir?
What is amprenavir, and how does it work (mechanism of action)?
This drug was discontinued as of October of 2007.
Amprenavir is an oral medication that is used for treating infections with the human immunodeficiency virus (HIV). It is in a class of drugs called protease inhibitors which, among others, includes indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir) and saquinavir (Invirase, Fortovase). During infection with HIV, the HIV virus multiplies within the body's cells. Viruses are released from the cells and spread throughout the body where they infect other cells. In this manner, HIV infection is perpetuated among new cells that the body produces continually. During the production of the viruses, new proteins are made. Some of the proteins are structural proteins, that, is, proteins that form the body of the virus. Other proteins are enzymes which manufacture DNA and other components for the new viruses. Protease is the enzyme that forms the new structural proteins and enzymes. Amprenavir blocks the activity of protease and results in the formation of defective viruses that are unable to infect the body's cells. As a result, the number of viruses in the body (the viral load) decreases. Nevertheless, amprenavir does not prevent the transmission of HIV among individuals, and it does not cure HIV infections or AIDS. Amprenavir was approved by the FDA in April 1999.
What are the side effects of amprenavir?
The most frequent side effects are headache, weakness, diarrhea, nausea and stomach pain. Amprenavir may also cause severe skin reactions and breakdown of red blood cells. The propylene glycol in the oral solution can cause seizures, stupor, increased heart rate, metabolic disturbance, and kidney failure. Like other protease inhibitors, use of amprenavir may be associated with redistribution or accumulation of body fat, increased cholesterol and worsening of diabetes.
What is the dosage for amprenavir?
The recommended dose is based on age, weight and the formulation. Individuals 4-12 years old or 13-16 years old and weighing less than 50 kg should receive 22.5 mg/kg twice daily or 17 mg/kg three times daily of the oral solution or 20 mg/kg twice daily or 15 mg/kg three times daily of the capsules.
Individuals 13- 16 years old who weigh 50 kg or more and individuals older than 16 years of age should receive 1400 mg twice daily of the oral solution or 1200 mg twice daily of the capsules.
The maximum daily dose is 2800 mg. Amprenavir capsules and solution are not interchangeable milligram for milligram. The oral solution should only be used when it is not possible to administer the capsules.
Amprenavir can be taken with or without food. However, foods high in fat may decrease the absorption of amprenavir and should be avoided.

SLIDESHOW
A Timeline of the HIV/AIDS Pandemic See SlideshowIs amprenavir safe to take if I'm pregnant or breastfeeding?
It is not known whether amprenavir is secreted in breast milk. Nevertheless, HIV-infected mothers should not breast-feed because of the potential risk of transmitting HIV to an infant that is not infected.
Summary
Amprenavir (Agenerase - discontinued brand) is a drug prescribed to treat infections with the human immunodeficiency virus (HIV). Side effects, drug interactions, and pregnancy safety information should be reviewed prior to taking this medication.
Multimedia: Slideshows, Images & Quizzes
Related Disease Conditions
-
Human Immunodeficiency Virus (HIV)
HIV (human immunodeficiency virus) infection left untreated causes AIDS (acquired immunodeficiency syndrome). The human immunodeficiency virus (HIV) is a type of virus called a retrovirus, which can infect humans when it comes in contact with tissues that line the vagina, anal area, mouth, or eyes, or through a break in the skin. HIV infection is generally a slowly progressive disease in which the virus is present throughout the body at all stages of the disease. Three stages of HIV infection have been described. The initial stage of infection (primary infection), which occurs within weeks of acquiring the virus, often is characterized by the flu- or mono-like illness that generally resolves within weeks. The stage of chronic asymptomatic infection (meaning a long duration of infection without symptoms) lasts an average of eight to 10 years without treatment. The stage of symptomatic infection, in which the body's immune (or defense) system has been suppressed and complications have developed, is called the acquired immunodeficiency syndrome (AIDS). The symptoms are caused by the complications of AIDS, which include one or more unusual infections or cancers, severe loss of weight, and intellectual deterioration (called dementia). When HIV grows (that is, by reproducing itself), it acquires the ability to change (mutate) its own structure. These mutations enable the virus to become resistant to previously effective drug therapy. The goals of drug therapy are to prevent damage to the immune system by the HIV virus and to halt or delay the progress of the infection to symptomatic disease. Therapy for HIV includes combinations of drugs that decrease the growth of the virus to such an extent that the treatment prevents or markedly delays the development of viral resistance to the drugs. The best combination of drugs for HIV are those that effectively suppress viral replication in the blood and also are well tolerated and simple to take so that people can take the medications consistently without missing doses.
-
AIDS (Acquired Immunodeficiency Syndrome)
AIDS is the advanced stage of HIV infection. Symptoms and signs of AIDS include pneumonia due to Pneumocystis jiroveci, tuberculosis, toxoplasmosis, seizures, weakness, meningitis, yeast infection of the esophagus, and Kaposi's sarcoma. Anti-retroviral therapy (HAART) is used in the treatment of AIDS.
Treatment & Diagnosis
- HIV-AIDS FAQs
- How To Reduce Your Medication Costs
- Pharmacy Visit, How To Get The Most Out of Your Visit
- Indications for Drugs: Approved vs. Non-approved
- Drugs: The Most Common Medication Errors
- Medication Disposal
- Dangers of Mixing Medications
- Drugs: Buying Prescription Drugs Online Safely
- Generic Drugs, Are They as Good as Brand-Names?
Medications & Supplements
- Drugs: Questions to Ask Your Doctor or Pharmacist about Your Drugs
- Drug Interactions
- ritonavir (Norvir)
- atazanavir (Reyataz)
- indinavir, Crixivan
- saquinavir (Invirase, Fortovase - discontinued)
- nelfinavir
- Agenerase (amprenavir) Side Effects, Warnings, and Drug Interactions
- fosamprenavir - oral, Lexiva
Prevention & Wellness

Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Reference: FDA Prescribing Information