If your current three-drug regimen isn't fully suppressing HIV levels in your body, should you add a fourth medication? That was precisely the question researchers explored in a study reported in the May 21 online edition of the Proceedings of the National Academy of Science. Seventeen HIVers with persistent detectable viral levels added a fourth, never-before-used drug to their regimens -- either Reyataz, Kaletra, or Sustiva.
The findings were surprising. None of the intensified regimens helped further lower blood-based viral levels. The researchers believe the data indicate that residual viremia is not the result of ongoing low-level viral replication but rather the release of previously hidden virus from reservoirs in the body where it evades the effects of antiretrovirals.