A Study of Foscarnet in the Treatment of HIV Infection in Patients Who Have Taken Zidovudine for a Long Time

It is hypothesized that the maximum AZT antiretroviral effect, which occurs at 8 weeks of therapy, will be enhanced by 2 weeks of foscarnet treatment, given at the same time by intermittent intravenous infusion. In addition, the further lowering of serum p24 antigen concentration that should occur during combined therapy might continue when oral AZT therapy is continued without foscarnet.

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.