TOXIC AIDS DRUG DERIVATIVE AS SMALLPOX TREATMENT?

A REDFLAGS ALERT

By Nicholas Regush

March 25, 2002- There has been a lot of media hype this week about the development of an oral drug that might be used to treat smallpox. That may seem like good news but this research effort must be watched very closely because the drug may prove to be much too toxic for human use. And given the need for a smallpox treatment, some of the drug’s negative effects may be downplayed.

The drug is called hexadecyloxypropl-cidofovir, or HDP-CDV. The reason for the hype is that HDP-CDV prevented the smallpox virus from replicating in lab tests and it prevented death in mice from a virus which is a close cousin.

However, HDP-CDV is a knockoff of cidofovir, which would have to be given intravenously to treat smallpox — and that’s not practical. Cidofovir is currently used to treat CMV (cytomegalovirus) retinitis in patients with AIDS.

One Red Flag is that cidofovir’s use in AIDS patients can be highly toxic, particularly to the liver. The drug has also been shown in lab tests to work well against other viruses, including HHV-6. Another Red Flag is that some researchers have expressed concern that cidofovir may be too toxic for regular treatment of HHV-6.

Just how HDP-CDV, a derivative of cidofovir, will behave in humans is unknown. Tests on healthy humans will begin shortly to determine its toxicity.

Unfortunately, media reports on HDP-CDV - as is often the case in reports on new drugs - have hyped the drug’s possibilities and ignored its potential difficulties.