There is a 4-week prestudy monitoring period during which AZT alone is administered on an outpatient basis, followed by a 2-week study period during which both intravenous foscarnet and oral AZT are administered in the hospital. During the subsequent 6-month follow-up period, oral AZT is administered and patients receive clinical evaluations. AZT is held for 48 hours on days before hospitalization and for 24 hours at the end of the hospitalization.