Efavirenz, marketed as SUSTIVA by DuPont Pharmaceuticals, only needs to be taken once a day and is taken in combination with other HIV drugs.

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The currently recommended treatment for newly diagnosed patients is a single pill (Atripla) taken dailythat combines three brand-name antiretrovirals - tenofovir (Viread), emtricitabine (Emtriva) and efavirenz (Sustiva).

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In the meantime, DuPont AIDS drug Sustiva fits in with Bristol's two HIV treatments, and DuPont anti-coagulant Coumadin meshes with Bristol's existing heart drugs, even though no patent protects it.

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