LUSAKA

Contamination of the AIDS drug, Viracept, has created panic among HIV-positive Zambians on antiretroviral therapy, who fear other AIDS drugs may not be safe.

Purity Mwamba, an HIV-positive housewife in the capital, Lusaka, told IRIN/PlusNews: "I may not be on Viracept, but I am deeply concerned as a person living with HIV and on ARVs [antiretroviral drugs]. If Viracept could be contaminated, other ARVs could be. We are therefore demanding an explanation from the government."

Roche, the Swiss company that manufactures the drug, announced that some batches of Viracept had been accidentally contaminated with mesylate (methane sulfonic acid ethylester), prompting a recall of the product from European Union markets.

The contaminant can cause cancerous tumours and genetic mutation that could harm unborn children if used during pregnancy. Roche found the contamination while investigating reports from patients that the Viracept tablets they were taking had an unusual smell.

Zambia's health minister, Brian Chituwo, last week announced the immediate discontinuation of the drug, mainly used in second-line treatment, and ordered health workers to explain the incident to affected people.

About 1.6 million of Zambia's 11.7 million people are infected with HIV, but only 100,000 are currently receiving treatment at state health facilities.

The government estimates that fewer than 1,000 of the people on ARVs - about one percent - are taking Viracept, but independent analysts say the number could be much higher.

According to Nkandu Luo, a former health minister, now an HIV/AIDS consultant, "There could be more people affected by this because some of them take Viracept as part of a combination therapy. Government should be speaking to Roche because the damage has been done. Roche should take responsibility for distributing contaminated drugs."

Roche introduced Viracept in 1998 as one of a class of ARV drugs called protease inhibitors, which prevent newly reproduced viruses from infecting other cells, thus slowing the spread of the HI virus in the body.

Samuel Mpuka, executive director of the Churches Health Association of Zambia, an umbrella organisation for church administered health institutions, said the contamination was scandalous and communities should be made more aware and be better informed of drug-related issues.

"Government should strengthen quality assurance mechanisms in this country - maybe there are many drugs that we are taking without actually ensuring their quality. People should know what they are taking," Mpuka said.

Minister Chituwo said all HIV-positive patients on Viracept would be checked by healthcare providers before being switched to other drugs. "Patients should not unilaterally decide to change drugs on their own, as the effects may be fatal," he cautioned.

There are fears that some patients will stop taking Viracept before health workers determine the best replacement drug, and interruptions in treatment can lead to the development of drug resistance.