July 19, 2005
Recently, at Thailand's 10th National Seminar on AIDS in Bangkok, scientists said the rate of drug resistance to locally made GPO-vir antiretroviral drug (ARV) treatment has increased dramatically over the past couple of years and is expected to get worse. The statements came soon after the government announced it would provide GPO-vir virtually free of charge to about 60,000 Thais needing treatment.
According to assistant professor Dr. Wasun Chantrtita, a member of Mahidol University's faculty of medicine at Ramathibodi Hospital, a study of about 300 patients receiving the generic combination of three HIV/AIDS drugs found increasing resistance to the treatment. Forty-nine percent of patients were resistant to lamivudine, 39.6 percent to stavudine, and 58 percent to nevirapine. Resistant patients switched to a more powerful regimen costing Bt10,000 ($239 US) per month, compared to Bt1,000 ($24 US) for GPO-vir, developed by the Government Pharmaceutical Organization.
Wasun said the high rate of drug-resistant HIV in the study indicates the spread of new infections already resistant to commonly used ARVs. New patients with primary drug-resistant HIV would have to use expensive ARV regimens. Patients resistant to nevirapine would likely be resistant to many other ARVs as well, Wasun added.
Dr. Ploenchan Chetchotisakd, an HIV/AIDS drug resistance researcher at Khon Kaen University, said nevirapine monotherapy to prevent mother-to-child transmission also causes drug resistance in mothers. Such resistance cuts the chances of the mothers using a large group of ARVs that make up 90 percent of the drugs given Thai HIV/AIDS patients.