Medications and Drugs
GENERIC NAME: amprenavir
BRAND NAME: Agenerase
DRUG CLASS AND MECHANISM: 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 also 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.
GENERIC AVAILABLE: No
PRESCRIPTION: Yes
PREPARATIONS: Capsule: 50 mg, 150 mg; Solution: 15 mg/ml
STORAGE: Store capsules and oral solution at room temperature, 20-25°C (68-77°F).
PRESCRIBED FOR: Amprenavir is used in combination with other anti-HIV drugs for the treatment of HIV infection.
DOSING:
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.
DRUG INTERACTIONS: Amprenavir interacts with many drugs. Some of the important interactions are mentioned
below. Viewers should consult their healthcare provider before combining any drugs with nelfinavir.
Amprenavir should not be used together with amiodarone (Cordarone), quinidine (Quinaglute,
Cardioquin), triazolam, ergot derivatives (e.g., Ergostat), triazolam (Halcion), midazolam
(Versed) and intravenous lidocaine (Xylocaine) because serious adverse effects could occur due to increased levels of these drug in the body.
Amprenavir also increases the concentrations in blood of rifabutin (Mycobutin) and sildenafil
(Viagra). Therefore, the doses of rifabutin and sildenafil should be reduced.
Amprenavir may increase the blood concentration of lovastatin (Mevacor), simvastatin
(Zocor), atorvastatin (Lipitor) and
cerivastatin (Baycol). This may result in an increased occurrence of myopathy (muscle pain) or rhabdomyolysis (muscle
breakdown).
St. John's wort and rifampin (Rifadin) decrease the concentration of amprenavir in the body, and this could reduce the effectiveness of amprenavir.
Amprenavir may decrease the effectiveness of oral contraceptives.
Amprenavir oral solution should not be administered with disulfiram (Antabuse), metronidazole
(Flagyl) or alcohol. Administration of the solution with these agents could cause severe side effects because of the substantial amount of propylene glycol in the oral solution.
Administration of amprenavir and didanosine (Videx) or antacids should be separated by one hour.
Supplemental vitamin E should not be used because amprenavir formulations contain more than the daily requirement of vitamin E.
PREGNANCY: Pregnant women should not use amprenavir oral solution. Amprenavir capsules have not been adequately evaluated in pregnant women.
NURSING MOTHERS: 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.
SIDE EFFECTS: 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.
Reference: FDA Prescribing Information
Last Editorial Review: 2/24/2001 7:09:00 PM
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.
- Drug Interactions - Learn about potential drug interactions you may be exposed to. Drug interactions can occur with prescription drugs, OTC medication, vitamins, herbs, and supplements.
- Human Immunodeficiency Virus - Read about HIV (human immunodeficiency virus) causes, symptoms, signs, treatment, prevention, transmission, facts, testing, research (vaccine), statistics and AIDS (acquired immunodeficiency syndrome).
- Drugs: What You Should Know About Your Drugs - Find out what you should know about your drugs such as side effects, warnings and precautions, storage information, and if a generic version is as good as the brand name.
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