Ten patients with
acquired immunodeficiency syndrome with newly diagnosed cytomegalovirus (CMV)
retinitis were treated with an induction regimen of intravenous
foscarnet, 60 mg/kg of
body weight, administered as a 2-h infusion and repeated every 8 h for 14 days. At the end of induction, 9 of 10 patients had stabilized (no new
retinal lesions and stable old lesions [7 patients]) or improved (decreased
retinal opacification [2 patients]). All eight patients with CMV in urine or blood upon entry into the study had negative urine and blood cultures at the end of induction. After induction
therapy, seven patients continued maintenance
foscarnet therapy, 60 mg/kg as a single daily infusion, 5 days/week. In six patients,
retinal lesions increased in size after 2 to 32 weeks of maintenance
therapy. One was invaluable because a
retinal detachment developed. Only 9 of 42 blood and urine cultures obtained during maintenance
foscarnet therapy yielded CMV, compared with 7 of 14 obtained prior to the initiation of
foscarnet induction
therapy (P = 0.04).
Foscarnet toxicity was mild and infrequent: elevation in serum
creatinine by 0.5 to 1.3 mg/dl over the base line (two patients), muscle twitching (three patients),
hemoglobin decrease by 1 mg/dl (two patients),
nausea (two patients), absolute neutrophil count decrease by 50% (one patient), rise in serum
phosphorus to greater than 5.5 mg/dl (four patients), and
proteinuria (two patients). Intermittently administered intravenous
foscarnet appears to be an effective, relatively nontoxic
therapy for CMV
retinitis. Additional studies to determine the optimal dosage for maintenance
therapy are needed, as are comparative trials with
ganciclovir.