Zidovudine (AZT) has produced the best clinical results in the drug therapy of AIDS to date, but it produces toxicity in approximately 50 percent of patients. Early data show that ddI possesses high antiviral activity and less toxicity than AZT. The most effective route and dose of ddI has yet to be determined.~Patients are given intravenous drug for 14 days with a 1 day washout period, then 76 weeks of oral medication. To expedite this safety study and still be able to maintain close monitoring of the patient's health, an overlapping dosing regimen is used. After 6 patients have been enrolled and at least 4 have completed 4 weeks of dosing without significant toxic effects, a second group of patients is started at the next dose level.~AMENDED: An alternative oral dosing formulation of ddI will be provided as a buffer powder blend packaged in sealed foil sachets in several strengths.
To determine the safety, pharmacokinetics (blood levels), and effectiveness of didanosine (ddI) when administered both intravenously and orally. After the maximum tolerated dose (MTD) is determined, an appropriate dosage regimen will then be established for Phase II and Phase III trials.~Zidovudine (AZT) has produced the best clinical results in the drug therapy of AIDS to date, but it produces toxicity in approximately 50 percent of patients. Early data show that ddI possesses high antiviral activity and less toxicity than AZT. The most effective route and dose of ddI has yet to be determined.