Single-Dose Viramune Causes More Resistance Than Thought

A single dose of the anti-HIV drug Viramune given to an HIV-positive woman during childbirth to prevent transmission of the virus to her infant can result in the development of drug resistance much more often than previously thought, according to three new studies in the July 1 edition of the Journal of Infectious Diseases. Two of the studies used highly sensitive genetic tests to gauge the development of drug resistance and found that from 40% to 65% of the women given a single dose of the drug developed some resistance to it. The third found that development of Viramune resistance occurred in 69% of women infected with HIV subtype C, but dropped to as little as 19% for those infected with HIV subtype A. 'As with any new medical intervention, there are inevitable tradeoffs with single-dose Viramune,' wrote physician Scott Hammer in an accompanying editorial in the journal. 'Although no major safety issues have arisen in mothers or infants taking this therapy, the emergence of drug resistance has created an increasing challenge to the scientific and public health communities.'