The first 50 patients enrolled into the study will be with investigators having prior ddC experience, specifically AIDS Clinical Trials Group (ACTG), or non-ACTG investigators who are listed in ddC protocols NIAID ACTG 012, 112, 047, 050, 106 (N3447), 114 (N3300), 119 (N3492), N3226, or investigators at any ACTG center or ACTG satellite centers with knowledge of ddC therapy.