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:
- Usual Dose
= 5 mg/kg, intravenously, once weekly, with probenecid and fluid
therapy.
- 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)
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