Classes
DEA Class; Rx
Common Brand Names; Lexiva
- HIV, Protease Inhibitors
Description
Protease inhibitor (PI)
For the treatment of human immunodeficiency virus (HIV) infection in combination with other antiretroviral agents
Prodrug of amprenavir; improved solubility compared to amprenavir allows for reduced pill burden
Indications
Indicated for the treatment of human immunodeficiency virus (HIV) infection in combination with other antiretroviral agents.
Contraindications
Hypersensitivity (eg, Stevens-Johnson syndrome) to fosamprenavir, amprenavir, or other component
Concomitant use of drugs that depend heavily on CYP3A4 for clearance; metabolite amprenavir is a strong CYP3A4 inhibitor; use with ritonavir another strong CYP3A4 inhibitor may have additive inhibitory effects; check Drug Interactions
Drugs that are contraindicated with fosamprenavir (with or without ritonavir) include lipid modifying agents (eg, lomitapide, lovastatin, simvastatin), alpha1-adrenoreptor agonists (eg, alfuzosin), antiarrhythmics (flecainide, propafenone), rifampin, ergot derivatives (dihydroergotamine, ergonovine, ergotamine, methylergonovine), cisapride, St. John’s wort, lurasidone, pimozide, sildenafil (when used for PAH), midazolam, and triazolam
Adverse Effects
- Nausea (30-50%)
- Rash (16-20%)
- Fatigue (11-15%)
- Diarrhea (5-13%)
- Increased triglycerides (11%)
- Increased serum lipase, ALT, AST (5-10%) in pts. treatment with concomitant ritonavir
- Vomiting (2-6%)
- Headache (2-4%)
- Pruritus (7-8%)
- Nausea (3-7%)
- Abdominal pain (≤ 2%)
- Increased hepatic transaminases (4-8%)
Warnings
New onset DM, exacerbation of pre-existing DM & hyperglycemia reported with unknown frequency/unknown causal relationship
Sulfonamide allergy
Monitor labs prior to and during treatment with Hepatitis B or C, or elevated transaminases
Few reports of spontaneous bleeding in patients. with Hemophilia A and B
During initial treatment, inflammatory response to indolent or residual opportunistic infections may occur and require treatment
Fat redistribution with “cushingoid appearance” and “buffalo hump” may occur
Increased risk for myocardial infarction (thought to be caused by protease inhibitors increasing risk of hyperlipidemia)
Monitor triglycerides and cholesterol levels before initiating, then periodically; initiate clinical management of lipid disorders as required
Combination treatment with ritonavir may lead to increased triglyceride level
Unknown effect on activity of subsequently administered protease inhibitors
Risk of immune reconstitution syndrome if used in combination with other antiretroviral drugs; autoimmune disorders (eg Graves disease, polymyositis, and Guillain-Barré syndrome) have also been reported to occur in the setting of immune reconstitution; however, the time to onset is more variable, and can occur many months after initiation of treatment
Vomiting more common in children
Cases of nephrolithiasis reported with fosamprenavir
Acute hemolytic anemia reported with amprenavir
Discontinue therapy if severe skin reactions including Stevens-Johnson syndrome occur
Pregnancy and Lactation
There are insufficient prospective pregnancy data from Antiretroviral Pregnancy Registry (APR) to adequately assess risk of adverse developmental outcomes
There is no information available on presence of amprenavir in human milk, the effects of the drug on breastfed infant, or effects of drug on milk production
Maximum Dosage
2,800 mg/day PO.
2,800 mg/day PO.
20 kg or more: 36 mg/kg/day (Max: 1,400 mg) PO with ritonavir; 60 mg/kg/day (Max: 2,800 mg) PO without ritonavir (not recommended by HIV guidelines).
2 years or older and at least 20 kg: 36 mg/kg/day (Max: 1,400 mg) PO with ritonavir; 60 mg/kg/day (Max: 1,400 mg) PO without ritonavir (not recommended by HIV guidelines).
2 years or older and 15 kg to 19 kg: 46 mg/kg/day PO with ritonavir; 60 mg/kg/day PO without ritonavir (not recommended by HIV guidelines).
2 years or older and 11 kg to 14 kg: 60 mg/kg/day PO with ritonavir; 60 mg/kg/day PO without ritonavir (not recommended by HIV guidelines).
2 years or older and 10 kg: 90 mg/kg/day PO with ritonavir; 60 mg/kg/day PO without ritonavir (not recommended by HIV guidelines).
younger than 2 years and 15 kg to 19 kg: 46 mg/kg/day PO with ritonavir.
younger than 2 years and 11 kg to 14 kg: 60 mg/kg/day PO with ritonavir.
younger than 2 years and less than 11 kg: 90 mg/kg/day PO with ritonavir.
15 kg to 19 kg: 46 mg/kg/day PO with ritonavir. HIV guidelines do not recommend use in infants under 6 months of age.
11 kg to 14 kg: 60 mg/kg/day PO with ritonavir. HIV guidelines do not recommend use in infants under 6 months of age.
less than 11 kg: 90 mg/kg/day PO with ritonavir. HIV guidelines do not recommend use in infants under 6 months of age.
Safety and efficacy have not been established.
How supplied
Fosamprenavir
tablet
- 700mg
oral suspension
- 50mg/mL
