According to a new report, ten years after they were introduced in Europe and North America, HIV/AIDS drugs remain effective but many patients are not being put on them soon enough.
Scientists carrying out a review of the treatment ten years on say treatments still work as well as they did initially.
Experts were always concerned that the AIDS virus would become resistant to the treatments and deaths would increase, but research published ahead of an international AIDS conference in Toronto later this month has shown this has not happened.
However though the combinations of drugs reduce mortality and progression to AIDS by about 80-90 percent, tuberculosis (TB) has become a deadly co-infection in many patients.
Professor Matthias Egger, of the University of Bern in Switzerland, says people need to be diagnosed and start treatment earlier and the drugs would achieve even more, but TB has become more of an issue.
The Antiretroviral Therapy Cohort Collaboration report based it's analysis on data of more than 22,200 HIV positive people in Europe and North America who started treatment between 1995 and 2003.
Current figures suggest that more than 40 million people worldwide are living with HIV/AIDS, and the majority are in sub-Saharan Africa.
According to the World Health Organisation as many as 1.3 million people in low- and middle-income countries were receiving HIV/AIDS drugs by the end of 2005.
Egger, a co-author of the study, says there is widespread consensus that patients should start treatment when their CD4 cell count, a measure of immune system response, dropped below 350 or if the person was unwell or showed symptoms of illness.
The scientists say people who start treatment with a CD4 count less than 200 have a higher risk of their illness progressing and of dying of HIV/AIDS than patients with a higher baseline count.