Viramune: Boehringer Ingelheim (BI), maker of the non-nuke Viramune (nevirapine), is issuing a “Dear Doctor” letter saying the med may spell trouble in first-line combos for women with CD4 counts over 250 and men over 400.

Viramune boosts those women’s risk of liver disease and rash almost tenfold (from 1.1 percent to 9.7 percent), the men’s almost seven times (from 0.7 percent to 3.6 percent). HIV expert Antonio Urbina, MD, says high CD4 counts invite danger because stronger immune systems are more likely to attack Viramune as an invader. But he says, “The warning applies only to those about to start Viramune. For those on it and doing well, there’s no need to stop or switch meds.”

“Viramune already had a black-box warning [for] fatal liver toxicity, including hepatitis and necrosis, in patients with high CD4 counts,” says an FDA spokesperson, adding that you should watch for the problems for 18 weeks, though the greatest risk falls in the first six weeks of treatment.