A Clinical Trial of Alternating and Intermittent Regimens of 2',3'-Dideoxycytidine and 3'-Azido-3'-Deoxythymidine in the Treatment of Patients With AIDS and Advanced ARC

AZT extends the survival of some patients with AIDS, and both AZT and ddC are known to inhibit the growth of HIV. When AZT or ddC is given continuously over a prolonged period of time, toxic effects occur that are not found when the drugs are given for 4 - 6 weeks. It is hoped that by alternating the drugs or by giving one drug intermittently, the toxic effects can be decreased without lowering the therapeutic effectiveness of the drugs. Patients will be assigned to 1 of 7 treatment groups. Both AZT and ddC will be given by mouth every 4 hours. One group will take AZT continuously for 52 weeks. One group will alternate 1 week of AZT with a week with no drug for 48 weeks and another group will alternate 1 week of ddC with a week of no drug for 48 weeks. Other groups will alternate AZT and either low-dose or high-dose ddC on a weekly basis or a monthly basis for 48 weeks. Patients will be seen weekly for the first 8 weeks of study and less often thereafter. Blood samples will be withdrawn frequently and evaluated for possible changes in the immune system, toxic effects, and possible changes in the amount of HIV in the blood. Lumbar punctures and skin biopsies will also be performed. AMENDED: All patients receiving continuous AZT will be switched to a lower dose of AZT if they have not already been switched. This is in accordance with results of NIAID ACTG 002, 016, and 019 which demonstrate that this dose of AZT delays progression of HIV symptoms.