Fosamprenavirdosage

Therapy-Naive Adults: Fosamprenavir 1,400 mg twice daily; fosamprenavir 1,400 mg once daily plus ritonavir 200 mg once daily; fosamprenavir 1,400 mg once daily plus ritonavir 100 mg once daily; fosamprenavir 700 mg twice daily plus ritonavir 100 mg twice daily.

Protease Inhibitor-Experienced Adults: Fosamprenavir 700 mg twice daily plus ritonavir 100 mg twice daily.

Pregnant Patients: Fosamprenavir 700 mg twice daily plus ritonavir 100 mg twice daily should only be considered in women who are already on a stable twice-daily regimen of fosamprenavir/ritonavir 700 mg/100 mg prior to pregnancy and who are virologically suppressed (HIV-1 RNA less than 50 copies per mL).

Pediatric Patients (aged at least 4 weeks to 18 years): Dosage should be calculated based on body weight (kg) and should not exceed adult dose.

Hepatic Impairment: Recommended adjustments for patients with mild, moderate, or severe hepatic impairment. Dosing Considerations

Fosamprenavir calcium tablets may be taken with or without food.

2.1 General

Dosing Information Fosamprenavir calcium tablets may be taken with or without food. Higher-than-approved dose combinations of fosamprenavir plus ritonavir are not recommended due to an increased risk of transaminase elevations. When fosamprenavir is used in combination with ritonavir, prescribers should consult the full prescribing information for ritonavir.

2.2 Adults Therapy-Naive

Adults

Fosamprenavir 1,400 mg twice daily (without ritonavir).

Fosamprenavir 1,400 mg once daily plus ritonavir 200 mg once daily.

Fosamprenavir 1,400 mg once daily plus ritonavir 100 mg once daily. o Dosing of fosamprenavir 1,400 mg once daily plus ritonavir 100 mg once daily is supported by pharmacokinetic data.

Fosamprenavir 700 mg twice daily plus ritonavir 100 mg twice daily. o Dosing of fosamprenavir 700 mg twice daily plus ritonavir 100 mg twice daily is supported by pharmacokinetic and safety data. Protease Inhibitor-Experienced Adults

Fosamprenavir 700 mg twice daily plus ritonavir 100 mg twice daily. Pregnancy

Fosamprenavir 700 mg twice daily plus ritonavir 100 mg twice daily. o Dosing of fosamprenavir 700 mg twice daily plus ritonavir 100 mg twice daily should only be considered in pregnant patients who are already on a stable twice-daily regimen of fosamprenavir/ritonavir 700 mg/100 mg prior to pregnancy and who are virologically suppressed (HIV-1 RNA less than 50 copies per mL). Lower exposures of amprenavir were observed during pregnancy; therefore, viral load should be monitored closely to ensure viral suppression is maintained. Data regarding use of other regimens of fosamprenavir (with or without ritonavir) in pregnancy are not available.

2.3 Pediatric

Patients (Aged at Least 4 Weeks to 18 Years) The recommended dosage of fosamprenavir in patients aged at least 4 weeks to 18 years should be calculated based on body weight (kg) and should not exceed the recommended adult dose (Table 1). Table 1. Twice-Daily Dosage Regimens by Weight for Protease Inhibitor-Naive Pediatric Patients (Aged 4 Weeks and Older) and for Protease Inhibitor-Experienced Pediatric Patients (Aged 6 Months and Older) Using Fosamprenavir Calcium Oral Suspension with Concurrent Ritonavir Weight Twice-Daily Dosage Regimen < 11 kg Fosamprenavir 45 mg/kg plus ritonavir 7 mg/kg When dosing with ritonavir, do not exceed the adult dose of fosamprenavir 700 mg/ritonavir 100 mg twice-daily dose. 11 kg - < 15 kg Fosamprenavir 30 mg/kg plus ritonavir 3 mg/kg 15 kg - < 20 kg Fosamprenavir 23 mg/kg plus ritonavir 3 mg/kg ≥ 20 kg Fosamprenavir 18 mg/kg plus ritonavir 3 mg/kg Alternatively, protease inhibitor-naive children aged 2 years and older can be administered fosamprenavir (without ritonavir) 30 mg per kg twice daily. Fosamprenavir should only be administered to infants born at 38 weeks’ gestation or greater and who have attained a postnatal age of 28 days. For pediatric patients, pharmacokinetic and clinical data:

do not support once-daily dosing of fosamprenavir alone or in combination with ritonavir.

do not support administration of fosamprenavir alone or in combination with ritonavir for protease inhibitor-experienced children younger than 6 months.

do not support twice-daily dosing of fosamprenavir without ritonavir in pediatric patients younger than 2 years. Other Dosing Considerations

When administered without ritonavir, the adult regimen of fosamprenavir calcium tablets 1,400 mg twice daily may be used for pediatric patients weighing at least 47 kg.

When administered in combination with ritonavir, fosamprenavir calcium tablets may be used for pediatric patients weighing at least 39 kg; ritonavir capsules may be used for pediatric patients weighing at least 33 kg.

2.4 Patients with

Hepatic Impairment See Clinical Pharmacology. Mild Hepatic Impairment (Child-Pugh Score Ranging from 5 to 6) Fosamprenavir should be used with caution at a reduced dosage of 700 mg twice daily without ritonavir (therapy-naive) or 700 mg twice daily plus ritonavir 100 mg once daily (therapy-naive or protease inhibitor-experienced). Moderate Hepatic Impairment (Child-Pugh Score Ranging from 7 to 9) Fosamprenavir should be used with caution at a reduced dosage of 700 mg twice daily without ritonavir (therapy-naive), or 450 mg twice daily plus ritonavir 100 mg once daily (therapy-naive or protease inhibitor-experienced). Severe Hepatic Impairment (Child-Pugh Score Ranging from 10 to 15) Fosamprenavir should be used with caution at a reduced dosage of 350 mg twice daily without ritonavir (therapy-naive) or 300 mg twice daily plus ritonavir 100 mg once daily (therapy-naive or protease inhibitor-experienced). There are no data to support dosing recommendations for pediatric patients with hepatic impairment.