Cidofovir

Background

• Acyclic nucleoside phosphonate that competes with cytosine nucleotides to inhibit viral DNA polymerase
• Indications: Adenovirus, CMV after solid organ transplantation, Cytomegalovirus, Herpes simplex virus

Spectrum of Activity

• Active against essentially all DNA viruses, including polyomaviruses (BK virus, JC virus), human papillomavirus, adenovirus, all of the human herpesviruses, poxviruses (including monkeypox virus and variola virus)
• Not active against hepatitis B virus or RNA viruses

Pharmacokinetics and Pharmacodynamics

• Unlike ganciclovir, it does not need phosphorylation by UL97
• Does not penetrate CSF

Dosing

• Should be given with probenecid 2 g IV prior to each dose

Safety

• Major adverse effect is dose-dependent, irreversible renal tubular necrosis, which may be prevented by probenecid
  • Contraindicated when creatinine >132 μmol/L, CrCl <55 mL/min, or urine protein ≥100 mg/dL (2+ proteinuria)
• Neutropenia
• Acute iritis