An Ascending, Single Oral Dose Pharmacokinetic Study of 3'-Deoxy-3'-Fluorothymidine (FLT) in Asymptomatic Human Immunodeficiency Virus (HIV)-Infected Subjects

Exclusion Criteria Co-existing Condition: Patients with the following conditions or symptoms are excluded: * Oral candida infection documented by morphology or by response to antifungal therapy within 2 months prior to study entry. * Temperature \> 37.8 degrees Centigrade. * Malignancy other than cutaneous basal cell carcinoma or cervical carcinoma in situ. * Significant chronic underlying medical illnesses which would prevent continuous participation in this clinical trial. Concurrent Medication: Excluded: \- Patients with the following are excluded: * Significant chronic underlying medical illnesses which would prevent continuous participation in this clinical trial. * Unwilling to sign informed consent. * Intolerant to zidovudine (AZT). * Oral hairy leukoplakia at any time prior to study entry. Prior Medication: Excluded within 7 days of study entry: * Antiretroviral drugs. * Immunomodulators. * Excluded within 30 days of study entry: * Any investigational drugs. Patients have the following: * HIV seropositivity by licensed ELISA test, confirmed by Western Blot analysis. * No symptoms as defined by: 1. Normal neurological exam. 2. Absence of the following: * Unintentional weight loss of greater than 10 pounds or more than 10 percent of usual body weight within 2 months prior to study entry. * Unexplained temperature \> 37.8 C on more than 5 consecutive days or on more than 10 days in any 30 day period in the one month prior to expected study entry. * Unexplained diarrhea defined by = or \> 3 liquid stools per day persisting \> 7 days within 2 months prior to expected study entry.