Mechanism of action	It is a pyrophosphate analogue that inhibits viral replication by targeting viral DNA polymerase.
Standard dosage	Induction therapy is 90 mg/kg IV over 2 h every 12 h for 2 to 3 weeks; maintenance therapy is 90 to 120 mg/kg IV over 2 h, every 24 h.
Contraindications	Hypersensitivity to foscarnet.
Main drug interactions	Increased cardiac toxicity is seen with a large number of drugs including tricyclic antidepressants, halothane, fluconazole, pentamidine. and antipsychotics. Concurrent use of cidofovir can cause nephrotoxicity.
Main side effects	Anemia (33 %), granulocytopenic disorder (17 %), nausea, vomiting, and diarrhea (30 %).
Special points	It is often used in conjunction with ganciclovir or cidofovir. Drug resistance can emerge.