Bristol-Myers Squibb ( BMY) and Gilead Sciences ( GILD) said Wednesday that the Food and Drug Administration has approved a new HIV drug that contains ingredients from three existing medications. The drug, Atripla, is the first once-a-day pill that can be used as a stand-alone therapy or in combination with other medications, the companies said. Atripla combines Sustiva from Bristol-Myers Squibb and Truvada from Gilead. Truvada is itself a combination pill, containing Gilead's Viread and Emtriva. The companies say Atripla should improve patient compliance thanks to simplified dosing. The companies established a joint venture in December 2004 to create the three-drug pill. "We appreciate the recognition by the FDA of this important therapeutic advance, and with their approval of Atripla in just over two months, patients will now have rapid access" to the drug, said John C. Martin, president and CEO of Gilead Sciences. Atripla will be available next week. Shares of Bristol-Myers Squibb fell 23 cents to $25.25; shares of Gilead slipped 8 cents to $61.68 by midafternoon.