Fosamprenavir Calcium(foss am pren’ ah ver)
Lexiva
PREGNANCY CATEGORY C
Drug Classes
Antiviral
Protease inhibitor
Therapeutic Actions
Antiviral activity; inhibits HIV protease activity, leading to the formation of immature, noninfectious virus particles.
Indications
Treatment of HIV infection in adults in combination with other antiretrovirals (the use of fosamprenavir with ritonavir is not recommended for protease inhibitor–experienced patients)
Contraindications and Cautions
Contraindicated with allergy to any component of the drug or to amprenavir; concurrent use of drugs dependent on the CYP3A4 system for clearance, lactation; if used with ritonavir, use of flecainide and propafenone is contraindicated.
Use cautiously with pregnancy, hepatic impairment, diabetes mellitus, lipid abnormalities, hemophilia, sulfonamide allergy.
Available Forms
Tablets—700 mg; suspension—50 mg/mL
Dosages
Adults
1,400 mg PO bid.
With ritonavir: 1,400 mg/day PO plus ritonavir 100 mg/day PO, 1,400 mg/day PO plus ritonavir 200 mg/day PO, or 700 mg PO bid with ritonavir 100 mg PO bid.
Protease-experienced patients: 700 mg PO bid with ritonavir 100 mg PO bid.
Pediatric patients
Therapy-naïve children 2–5 yr: 30 mg/kg oral suspension PO bid; do not exceed 1,400 mg bid.
Therapy-naïve children 6 yr and older: 30 mg/kg oral suspension PO bid; do not exceed 1,400 mg bid. Or, 18 mg/kg oral suspension PO with ritonavir 3 mg/kg PO bid; do not exceed 700 mg fosamprenavir plus 100 mg ritonavir bid.
Therapy-experienced children 2–5 yr: Safety and efficacy not established.
Therapy-experienced children 6 yr and older: 18 mg/kg oral suspension with 3 mg/kg ritonavir PO bid; do not exceed 700 mg fosamprenavir with 100 mg ritonavir bid.
Patients with hepatic impairment
Child-Pugh score 5–6: 700 mg PO bid without ritonavir (therapy-naïve patients) or 700 mg PO bid plus 100 mg/day ritonavir (therapy-naïve or protease-inhibitor–experienced patients).
Child-Pugh score 7–9: 700 mg PO bid without ritonavir (therapy naïve) or 450 mg PO bid with 100 mg/day ritonavir PO.
Child-Pugh score 10–15: 350 mg PO bid without ritonavir (therapy naïve) or 300 mg PO bid with ritonavir 100 mg/day PO.
