Some HIV-positive people may be able to take a reduced dose of the HIV med efavirenz (in Sustiva and Atripla)—if the regular dose produces higher than normal levels of the drug in their blood. Dutch investigators reported this in the October Journal of Acquired Immune Deficiency Syndromes—and said that the lower dose still effectively suppressed HIV.  For some people, this could translate to fewer side effects: Often, those with high efavirenz blood-levels suffer depression, troublesome dreams and sleep interruption.

The only hitch: Efavirenz levels were gauged using therapeutic drug monitoring (TDM, measuring concentrations of drugs in your bloodstream)—not commonly available in this country. So call this a vote for making TDM accessible in the United States.