In a letter sent this week to physicians and other health care providers, drugmaker Bristol-Myers Squibb warns that HIV patients could experience early virologic failure when beginning antiretroviral therapy with three-drug regimens containing its drug Videx EC and Gilead Sciences' Viread, plus one of two other drugs--Sustiva, also from BMS, or Viramune, from Boehringer Ingelheim. According to the letter, data from studies of the drugs show that treatment-naive patients beginning either of these two regimens are at a significantly higher risk of developing early virologic failure than those beginning therapy with other regimens. The risk may be particularly high for HIV patients with high baseline viral loads. BMS says in the letter that clinicians should use caution when coadministering Viread, Videx EC, and either Sustiva or Viramune in treatment-naive patients with high baseline viral loads. The company also says further studies are under way to better understand the clinical implications of the current data. Physicians with questions about the warning can contact the BMS Virology Medical Services Department at (800) 426-7644 and select option 3.