Abstract
It has often been stated that the central questions in therapy for human immunodeficiency virus (HIV) infection are the same now as they were when the epidemic started. When do we start therapy, what do we start with, when should we switch, what constitutes failure of therapy, and why do our therapies fail? Information from clinical trials of various anti-HIV treatments, along with in vitro observations, has narrowed the choices. Often, the design and completion of these trials lag behind practice, but they still serve several crucial purposes. The studies confirm what we think we know, disprove beliefs based on . . .