Comparison of ddI Versus Zidovudine in HIV-Infected Patients

To compare the effectiveness and toxicity of didanosine (ddI) and zidovudine (AZT) in patients with AIDS, advanced AIDS-related complex (ARC), or asymptomatic infection with CD4 counts < 200 cells/mm3. AZT is effective in reducing mortality in patients with AIDS who receive the drug after the first episode of Pneumocystis carinii pneumonia (PCP) and in patients with advanced ARC. However, AZT therapy has been associated with significant toxicities. In addition, the effectiveness of AZT appears to decrease during the second and third years of therapy. For these reasons, the development of alternative therapy that would be at least as effective but less toxic is of great importance. The drug ddI is an antiviral agent that inhibits replication (reproduction) of HIV with less apparent toxicity than AZT. AZT is effective in reducing mortality in patients with AIDS who receive the drug after the first episode of Pneumocystis carinii pneumonia (PCP) and in patients with advanced ARC. However, AZT therapy has been associated with significant toxicities. In addition, the effectiveness of AZT appears to decrease during the second and third years of therapy. For these reasons, the development of alternative therapy that would be at least as effective but less toxic is of great importance. The drug ddI is an antiviral agent that inhibits replication (reproduction) of HIV with less apparent toxicity than AZT. AMENDED: 9/28/90 Patients are assigned to one of 2 treatments under a double-blind, randomly allocated, experimental design if their duration of prior AZT therapy is 0 to 16 weeks. (Patients who entered with no more than 16 weeks prior AZT and who were randomized to ddI will continue to be dosed at that level, adjusted for weight, and followed as originally planned.) Patients are assigned to one of 3 treatments as explained prior to this amendment if their duration of prior to AZT therapy is greater than 16 weeks. Original design: Patients are assigned to one of three treatments under a double-blind randomly allocated experimental design. ddI will be administered at two dose levels. It is anticipated that patients will be seen as outpatients every 2 weeks for the first 4 weeks of the study and monthly thereafter. This study continues for at least 18 months after the entry of the first subject.