While obtaining a peripheral venous blood sample from a patient with the acquired immunodeficiency syndrome (AIDS), a 35-year-old phlebotomist is injured by a bloody 18-gauge needle attached to a syringe. The patient has been taking didanosine and stavudine for more than six months, but her quantitative plasma human immunodeficiency virus (HIV) RNA titer and CD4 T-lymphocyte count have not been measured for many weeks. What is the appropriate postexposure treatment for the phlebotomist?.