Brand name: Vistide
Background: Since 1996, Cidofovir, a drug in the acyclic nucleoside phosphonates class, has been available for treatment of AIDS patients with CMV retinitis, but it has the ability to work for a wide range of DNA viruses, including poxviruses. Cidofovir has shown to be more effective on poxviruses than ribavirin, acyclovir, and methisazone.
Mechanism of action: It is not exactly known how the drug works on poxviruses, but from prior research of the drug on CMV it has been shown to selectively block viral DNA synthesis since it is a monophosphate nucleotide analog of dCTP. This can inhibit viral DNA polymerase since it is incorporated into the viral DNA and thus disrupts further attachment of nucleotides. Cidofovir is different than acyclovir since it does not require thymidine kinase to phosphorylate it. . In addition, cidofovir is unique from other nucleoside analogs because it has the ability to inhibit viral DNA synthesis and replication for prolonged periods of at least 7 days after the first exposure.
Recommended dose: One dose per week for 2 weeks of 5 mg per kg of body weight, and then one dose every other week after that.
Side effects: Renal and ocular toxicity can result, however, both are usually resolved after treatment has ended. Administering probenecid orally and saline hydration intravenously can minimize renal toxicity when cidofovir is given concurrently. Otherwise, there have been no significant systemic side effects aside from local inflammation at the application site.
Clercq E.D. “Cidofovir in the treatment of poxvirus infections.” Antiviral Research. 55(1):1-13. July 2002.
Kimon Z.C. “Cidofovir: An Overview.” Accessed Nov. 27, 2005.< http://patients.uptodate.com/topic.asp?file=viral_in/18942&title=Papillomavirus+infection>