Classifications: antiviral agent; antiretroviral agent; protease inhibitor; Therapeutic: antiretroviral; protease inhibitor
Pregnancy Category: C
50 mg capsules; 15 mg/mL oral solution
Amprenavir inhibits the activity of HIV-1 protease enzyme and thus prevents the cleavage of viral polyproteins essential
for the maturation and proliferation of the HIV-1 virus. Amprenavir results in reduction of the viral load (HIV-RNA) in
the plasma and an increase in the CD4 lymphocyte cell count.
The protease inhibitor activity results in the formation of immature, noninfectious viral particles. Effectiveness is measured
by reduced viral particle count.
Treatment of HIV infection in combination with other antiretroviral agents.
Renal failure. Prior sensitivity to amprenavir; oral solution in children <4 y, infants, neonates; pregnancy (category C),
History of hypersensitivity to other protease inhibitors (e.g., indinavir, ritonavir, saquinavir); hypersensitivity to sulfonamides;
hepatic dysfunction; diabetes mellitus; diabetic ketoacidosis, hemophilia A and B; vitamin K deficiencies; anticoagulant
therapy, oral contraceptives; coadministration with rifampin or sildenafil; antimicrobial resistance, hypercholesterolemia,
hypertriglycerides, hyperglycemia, females, children, hepatic or renal impairment.
Route & Dosage
Adult/Adolescent: PO 1200 mg capsules b.i.d.
Child (412 y or <50 kg): PO 20 mg/kg b.i.d. capsules or 15 mg/kg t.i.d. capsules (max: 2400 mg/d); 22.5 mg/kg b.i.d. oral solution or 17 mg/kg t.i.d.
Child-Pugh score of 58: give 450 mg b.i.d.; Child-Pugh score 912: give 300 mg b.i.d.
- Give without regard to food, BUT not with high fat meal.
- Capsules & oral solution are not interchangeable on mg-for-mg basis.
- Give 1 h before/after antacid.
- Store tablets at 20°25° C (68°77° F). Do not refrigerate.
Adverse Effects (≥1%)CNS: Oral/perioral paresthesia,
peripheral paresthesia, depression
, mood disorders. GI: Nausea, vomiting, diarrhea,
taste disorders, increased triglycerides, hyperglycemia. Skin: Rash, Stevens-Johnson syndrome.
Administration with amiodarone, bepridil, dihydroergotamine, ergotamine, lidocaine, midazolam, quinidine, triazolam,
and tricyclic antidepressants
may cause life-threatening reactions; rifampin, rifabutin, oral contraceptives
, phenobarbital, phenytoin, carbamazepine
may increase dihydroergotamine, ergotamine sildenafil
concentrations and toxicity; amprenavir
may decrease methadone
levels; monitor INR with warfarin; oral solution
may cause antabuse reaction with disulfiram, metronidazole. Food:
Decreased absorption with high-fat meal. Herbal: St. John's wort
may decrease antiretroviral activity.
Oral solution is less absorbed than capsules. Peak:
12 h. Distribution:
90% bound to plasma
In liver by CYP3A4. Elimination:
14% in urine, 75% in feces as metabolites. Half-Life:
Assessment & Drug Effects
- Monitor for therapeutic effectiveness which is indicated by elevated CD4 count & decreased HIV RNA copies.
- Monitor for & promptly notify physician of severe skin rash.
- Lab tests: Monitor blood glucose & HbA1c, Hgb & Hct, and lipid profile at periodic intervals.
- Note: Monitor blood levels for coadministered drugs including amiodarone, lidocaine, phenobarbital, phenytoin, quinidine, tricyclic
antidepressants; monitor PT and INR with warfarin.
Patient & Family Education
- Follow directions for taking this drug (see ADMINISTRATION).
- Take drug exactly as prescribed at the indicated times. Missed dose: if less than 4 h, wait until the next scheduled dose;
otherwise, take immediately.
- Do not take supplemental vitamin E with this drug unless approved by physician.
- Notify physician promptly about skin rash, nausea, vomiting, diarrhea, numbness or tingling around mouth or hands & feet.
- Inform physician of all other prescription/nonprescription drugs being taken. Serious interactions can occur.
- Use alternative barrier contraceptives rather than hormonal contraceptives while taking this drug.
- Note: Redistribution/accumulation of body fat may occur.
- Note: Diabetics may experience loss of glycemic control.