Drug Resistance Is Rarer Than Expected

Fewer HIVers taking antiretroviral drugs develop virus that is resistant to the medications than expected, according to a study in the March 4 edition of the British Medical Journal. Researchers examined the records of more than 16,000 people taking antiretrovirals between 1996 and 2002. They found that about 15% of the patients developed resistance to one or more of their medications, a figure lower than expected. The study also shows that antiretroviral therapy is very effective in controlling HIV replication. The percentage of study subjects with high viral load measurements dropped from 89% in 1996, when combination therapy was introduced, to 23.5% in 2002, according to the researchers. The percentage of patients with low CD4-cell counts fell from 57% in 1996 to 15% in 2002, thanks to successful treatment. The researchers say that while the lower-than-expected rate of drug resistance is encouraging, it still can severely limit the treatment options for people who develop it.