Patient Treatment

Potential Treatments

Vaccinia Immune Globulin is NOT effective against smallpox infection and should not be used.

Antiviral Drugs

No antiviral drug is currently approved for the treatment of smallpox. Recent studies suggest that the antiviral drug cidofovir might be useful as a therapeutic agent.

Cidofovir (Vistide), a nucleoside analog DNA polymerase inhibitor, might prove useful in preventing smallpox infection if administered within 1 or 2 days after exposure (John Huggins, PhD, oral communication, 1998). Cidofovir is active against some DNA viruses. (22:V3:57) (9:6) A USAMRID virologist named John Huggins, ran some experiments and found that a drug called Cidofovir could be used to successfully treat monkeys infected with monkeypox. (15:101) Working in the Maximum Containment Lab at the CDC in 1995, Huggins also found that cidofovir seemed to work against smallpox in a test tube. (15:101)

The potential utility of this drug is limited, given the fact that it must be administered intravenously and its use is often accompanied by serious renal toxicity. (9:6) Potential toxicities associated with the use of Cidofovir are nephrotoxicity, with proteinuria and elevated creatinine, and also neutropenia. In addition, use of cidofovir for the treatment of smallpox would be an off label use. The FDA approved only for treatment of CMV retinitis in persons with AIDS. (22:V3:57)

The dosing and toxicity associated with Cidofovir are:

  1. Usual Dose = 5 mg/kg, intravenously, once weekly, with probenecid and fluid therapy.
  2. Cleared in kidneys.

Antiviral therapy with cidofovir or other drugs subsequently found to have anti-variola activity might be considered, but would be used under an investigational new drug protocol by an infectious disease specialist. (22:V3:56) An antiviral drug for smallpox could also be used to treat people who had bad reactions to the existing vaccine; it could be a safety net for immune compromised people in case millions of people needed to be vaccinated for smallpox quickly. (15:102) 

    Top of Page