Dual combination therapy, described as sub-optimal by WHO guidelines on antiretroviral therapy in resource-limited settings, was associated with a 57% reduction in the death rate amongst people with advanced HIV infection in northern Thailand, according to a report published in the February 14th edition of the Journal of Acquired Immune Deficiency Syndromes.
The study is a retrospective cohort analysis of patients treated between 1995 and 1999, at Lampang Hospital in Chiang Mai, northern Thailand.
1110 patients attended the clinic (34% female), 70% were symptomatic; CD4 counts within the first year of diagnosis were available for 681 patients, and the median CD4 count, was 90 cells/mm3 (25-290). 257 patients already had a CD4 count below 50 cells/mm3 at this point.
Follow-up data were available for 1081 patients, of whom 607 died during the follow-up period. Data of patients lost to follow-up before October 1999 were censored at the time of last visit. 1175 patient years of follow-up were available for analysis.
The mortality rate per 100 person years of follow-up was 79.6% in those with baseline CD4 counts below 100 cells/mm3.
Twenty-three per cent of patients received antiretroviral therapy during the observation period. Seventy nine patients received monotherapy, usually zidovudine, whilst 130 patients were treated with dual therapy (usually AZT and ddI or ddC). Nineteen patients were treated with triple regimens.
The median duration of therapy was 211 days for patients treated with monotherapy, and 367 days for patients treated with dual therapy (19 patients treated first with AZT before commencing dual therapy were counted in the latter group).
A clear survival advantage was evident for patients with CD4 cell counts below 200 cells/mm3 who received dual therapy. The relative reduction in mortality for patients who received dual therapy compared to no therapy at all was 57% (35% for monotherapy), similar to the extent of benefit seen in the Delta and ACTG 175 studies that first reported the benefits of dual combination therapy in 1995.
“As long as the gap between the cost of suboptimal therapy and HAART is immense, clinicians working in resource-limited countries will continue to face the dilemma of treating a smaller number of patients with optimal therapy or a larger number with suboptimal therapy”, the authors comment.
“Reducing the effectiveness of future triple therapy among patients exposed to dual therapy is …[a] concern. Nevertheless, if not treated with any ARV drug, most patients with a low CD4 count will soon die.”
The authors also note that it would have been impossible for them to assess the additional benefit and cost-effectiveness of generic-based triple therapy without performing this analysis.
Further information on this website
Initial regimens in resource-limited settings
Antiretroviral therapy in resource-limited settings
Reference
Pathipvanich P, et al. Survival benefit from non-highly active antiretroviral therapy in a resource-constrained setting. Journal of Acquired Immune Deficiency Syndromes 32: 157-160, 2003.