Foscarnet

Background

• Inhibits DNA polymerase in human herpesviruses
• Indications: CMV after hematopoietic stem cell transplantation, CMV after solid organ transplantation, Cytomegalovirus, Herpes simplex virus, Herpesviridae, Post-transplant acute limbic encephalitis

Spectrum of Activity

• Active against all human herpesviruses

Pharmacokinetics and Pharmacodynamics

• CSF penetration 66% of serum levels

Dosing

Pediatric Dosing

• Induction: foscarnet 60 mg/kg IV q8h or 90 mg/kg IV q12h
• Maintenance: foscarnet 90 to 120 mg/kg IV q24h

Safety

• Nephrotoxicity, usually reversible
• Electrolyte abnormalities, including hypocalcemia, hypophosphatemia, hyperphosphatemia, hypomagnesemia, and hypokalemia
• Seizures
• Genital ulcers
• Anemia
• Nausea