Foscarnet

Administration

• Type: Antiviral
• Dosage Forms:
• Routes of Administration: IV
• Common Trade Names: Foscavir

Adult Dosing

• CMV retinitis: 90 mg/kg IV q12h OR 60 mg/kg IV q8h for 2-3 weeks, then maintenance 90-120 mg/kg IV daily
• HSV resistant to acyclovir, immunocompromised: 40 mg/kg IV 2-3 times daily
• VZV resistant to acyclovir, HIV+: 90 mg/kg IV q12h

Special Populations

• Pregnancy Rating: C
• Lactation risk: Infant risk cannot be ruled out
• Renal dosing: Complicated dose adjustment required!
• Hepatic dosing: No adjustement

Contraindications

• Allergy to class/drug

Adverse Reactions

Serious

• Hyperphosphatemia, hypophosphatemia, hypocalcemia, hypokalemia, hypomagnesemia
• Pancreatitis
• Pancytopenia
• Renal failure, renal impairment
• Seizure

Common

• Nausea, vomiting, diarrhea
• Anemia, granulocytopenic disorder
• Headache
• Fever

Pharmacology

• Half-life: 3.3-4h
• Metabolism:
• Excretion: Renal

Mechanism of Action

• inhibits pyrophosphate binding on viral DNA polymerases

See Also

• CMV
• HSV
• Immunocompromised antibiotics