AMPRENAVIR

Antiviral Activity

Used in the treatment of HIV-1 infection in combination with at least two additional antiretroviral agents
Active against susceptible HIV strains

Pregnancy Risk Factor

Category C

Contraindication/Precaution

Hypersensitivity to amprenavir or any component
Hypersensitivity to sulfonamides. There is a potential for cross-sensitivity between drugs in the sulfonamide class and amprenavir.
HIV-infected mothers should not breast-feed in order to avoid transmission to a non-infected newborn
Contraindicated in patients with renal failure
Should not be administered concurrently with astemizole, bepridil, cisapride, disulfiram, dihydroergotamine, ergotamine, lovastatin, metronidazole, midazolam, rifampin, simvastatin and triazolam. 
Use caution in the presence of impaired liver function 
Use caution with patients with hemophilia A and B

Mechanism of Action

Inhibitor of HIV protease
Peptide-like substrate analogue that binds to the protease active site and inhibits the activity of the enzyme
Prevents cleavage of the viral polyproteins resulting in the formation of immature noninfectious virus particles

Pharmacodynamics/Kinetics

Metabolism: 
liver, cytochrome P450 CYP3A4 enzyme system
Half-life: 
7.1-10.6 h
Elimination: 
excreted mostly in feces and some in urine

Dosage

Children: 

>4 to 12 years old or if <50 kg: (max 2400 mg/day)   20 mg/kg PO bid or 15 mg/kg PO tid >13 years old: 
1200 mg PO bid

Adults:  

1200 mg PO bid

Dosage In Renal Failure

Amprenavir oral solution is contraindicated in patients with renal failure
Cr. clearance (ml/min):
N/A
Dialysis
Hemo: N/A
CAPD:  N/A