Alternative and less toxic treatments need to be investigated for the treatment of HIV infection. Studies have shown that the dideoxynucleosides ddI and ddC may be effective antiretroviral agents in the treatment of HIV-infected individuals. However, ddI and ddC have yet to be compared on the basis of patient survival, drug tolerance, immunologic and virologic effectiveness, and the incidence of opportunistic infection or opportunistic malignancy. Results of this study will yield information regarding the relative therapeutic benefits and toxicities of each drug while providing alternative treatment to patients who are unable to tolerate or have had progression of disease while on AZT.~After baseline screening, patients are randomized to one of two treatment arms (ddI or ddC). Subjects are evaluated biweekly for the first 4 weeks of study, at 2 months, and every other month thereafter. Three dose levels of ddI (based on patient's weight at study entry) are compared with two dose levels of ddC (also based on patient weight). Patients who reach a new progression-of-disease primary endpoint after at least 12 weeks of treatment or a drug intolerance endpoint have the option of switching over to the alternate study drug; however, participants are encouraged to remain on their original drug assignment whenever possible. For any switchover, patients must be off the originally assigned drug for at least 72 hours before switching. Only one switchover is allowed.
To evaluate and compare the effectiveness and toxicity associated with didanosine ( ddI ) and zalcitabine ( dideoxycytidine; ddC ) in patients with HIV infection who are intolerant of or have failed zidovudine ( AZT ) therapy.~Alternative and less toxic treatments need to be investigated for the treatment of HIV infection. Studies have shown that the dideoxynucleosides ddI and ddC may be effective antiretroviral agents in the treatment of HIV-infected individuals. However, ddI and ddC have yet to be compared on the basis of patient survival, drug tolerance, immunologic and virologic effectiveness, and the incidence of opportunistic infection or opportunistic malignancy. Results of this study will yield information regarding the relative therapeutic benefits and toxicities of each drug while providing alternative treatment to patients who are unable to tolerate or have had progression of disease while on AZT.