Lynda Gledhill
A recent study published in a medical journal suggests that DMF, the main chemical constituent of Virodene, may activate the HIV virus.
South African medical experts who reviewed the article said it raises serious questions about Virodene and its potential affect on Aids patients.
The study showed that several industrial solvents, including DMF (dimethylformamide), stimulate the part of HIV that controls how much of the virus is made. Not only did the solvents activate HIV, they also caused other HIV activators to replicate the vi rus more efficiently.
“Virodene may be doing more harm than good,” said one Aids researcher, who asked not to be named. “Any amount of activation cannot be good news, even if [DMF] then helps block HIV.”
Members of the Medicines Control Council (MCC) say the article is one more reason to doubt the efficacy of Virodene, and they have forwarded the study to the Pretoria researchers promoting the drug.
However, Dr Hugo Snyckers, interim administrator of Cryopreservation Technologies, the company that holds the Virodene patent, said the article does not have a direct bearing on the team’s research. “We will reply to this, but we don’t believe it affects what we are doing,” he said, adding that the details were highly scientific and should not be debated in a newspaper.
The study, which appeared in the September 1997 issue of Aids Research and Human Retroviruses, was led by a researcher at the University of Washington. The researchers say they don’t know what it is that makes the solvents stimulate the virus.
Several other medical journal articles have examined the effect of industrial solvents on the HIV virus, with mixed results.
Doctors who treat Aids patients said they are aware of the research. “This is not new. [DMF] was tested as a herpes drug and shown to have no value at all,” said Dr Steve Miller, a Johannesburg general practitioner. “No one has shown it to be beneficial. “
A study cited by the Virodene researchers showed that another solvent, DMSO, may help inhibit the HIV virus. However, the concentration levels were much higher than what they proposed to use.
“At those levels DMF would be toxic for rats, never mind humans,” said Dr Paul Johnson, another doctor who treats Aids patients.
The Virodene researchers were criticised last year by a University of Pretoria committee investigating their research for misinterpreting available literature and confusing DMF and DMSO.
The MCC halted human testing of Virodene last year because DMF is a toxic chemical known to cause liver damage in humans. Other researchers emphasised that laboratory results should not be extrapolated to humans.
“The solvents may switch on the replicator in a test tube,” Miller said, “but we don’t know how much would get into the human body.”
Deputy President Thabo Mbeki and Minister of Health Nkosazana Zuma have criticised the MCC for blocking further Virodene research. “[Mbeki] is saying the MCC needs to keep an open mind,” said his representative, Ricky Naidoo. “These issues need to be put to rest once and for all.”
The Virodene researchers are currently revising a research protocol to submit to the MCC and hope to have it ready by May, Snyckers said.