AIDS activists and researchers are at loggerheads over the planned South African trial of a lower dose version of the controversial antiretroviral stavudine, which has in the past been responsible for debilitating side-effects in HIV patients.
The main adverse effect is peripheral neuropathy, which can be corrected by reducing dosage.
The symptoms of peripheral neuropathy include burning, stiffness, prickling, tingling, and numbness or a loss of feeling in the toes and soles of the feet. Sometimes the nerves in the fingers, hands, and wrists are also affected.
Stavudine is also one of the most likely ARVs to cause lipodystrophy, and for this reason it is no longer considered an appropriate treatment for most patients in developed countries and is no longer recommended by the World Health Organisation.
However, due to its low price, it is still widely used in the developing world.
Lipodystrophy is the redistribution of fat in the body, which manifests as excess, or lack of, fat in various regions of the body. People can have sunken cheeks and/or "humps" on the back or back of the neck (also referred to as buffalo hump).
In the one camp, the Treatment Action Campaign, Medecins Sans Frontieres (Doctors without borders) and the Treatment Action Group have serious concerns about the proposed trial.
They are concerned that stavudine is more toxic than tenofovir (the drug which replaced stavudine in the government treatment programme), making it an inferior treatment.
Patients' poor tolerance means that they are more likely to not adhere to treatment and will have to be switched to more expensive second-line treatment when they fail first line treatment.
MSF's experience in Lesotho has also shown that the costs related to treating the side effects of stavudine neutralised any cost-saving by placing patients on the cheaper option.
The group also claims that stavudine compromises second-line treatment in that it affects the tolerability of the next level of drugs, the longer the patient has been on the failing first line regimen.
In addition, stavudine must be taking twice-daily (as opposed to tenofovir's once-daily), tenofovir is recommended for HIV Hepatitis B co-infection and massive community opposition to the return of stavudine.
Those supporting the stavudine trial claim that tenofovir is unaffordable to most African countries and thus unsustainable.
However, the TAC/MSF group said this argument might become irrelevant by the end of the trial, which could take nine years to complete.
The price of tenofovir has more than halved in the last several years and is expected to decrease further as demand increases.
The stavudine research team led by the Wits Reproductive Health and HIV Institute's Professor Francois Venter said the evidence that stavudine produced bad side-effects was at the 40mg dose, but that it has been as effective as tenofovir at suppressing HIV at half this dose. However, this has not been rigorously established, which is why he believes the study is needed.
"Tenofovir is expensive and in most African countries its use is unsustainable. However, we have been hopelessly overdosing patients on stavudine, just like we did with AZT 15 years ago," said Venter.
Venter said stavudine was still widely used across Africa and that it made sense to establish how the drug could be used more safely.
He said all drugs had problems at the wrong dose and that stavudine would be tested to exactly the standards to which tenofovir was tested.
"The study design is not controversial, it follows standard scientific practice and could be run in a rich country," said Venter, adding that the study had been through rigorous international scientific and ethics scrutiny, and will be rigorously monitored throughout.
Venter has in the past been a staunch ally of the activist movement, including TAC and MSF, placing the parties in the unfamiliar position of opposing camps.
"It's awkward and not a position we are used to being in. We have worked together very well in the past and I am sure we will be able to take this debate forward in a collegial manner," said Venter.
A decision by the Gates Foundation to fund the study has also seen activists sending an impassioned plea to Bill and Melinda Gates, urging them to rethink their support for the trial.
The matter has also come to a head with the recent stock outs of tenofovir after the appointed pharmaceutical companies failed to produce their quotas.
However, moves to place patients on stavudine in areas where there were shortages have been met with resistance.
This week, patients and TAC activists staged a sit-in at the Village Community Health Centre in Lusikisiki in the Eastern Cape after they were told their tenofovir would be replaced with stavudine.
Health officials reportedly fetched a supply of tenofovir from the depot in an effort to placate angry patients.
Activists have launched a petition against the study.