Monitoring plasma levels of ganciclovir in AIDS patients receiving oral ganciclovir as maintenance therapy for CMV retinitis

Objective To investigate whether low ganciclovir serum levels in patients o n maintenance oral ganciclovir therapy are associated with recurrence of CM V retinitis. Methods A prospective study of the plasma concentration of ganciclovir afte r initiation of maintenance oral ganciclovir therapy in 14 AIDS patients wh o had recovered from acute cytomegalovirus (CMV) retinitis. Results Five of the 14 patients exhibited a mean time to recurrence of 37 d ays. The mean trough plasma concentration of ganciclovir in these patients after 1 month of oral ganciclovir therapy, was 0.40 +/- 0.30 mg/L. Nine pat ients had a mean time of progression of 263 days. The mean trough plasma co ncentration of ganciclovir in the latter patients was 0.80 +/- 0.60 mg/L. Conclusions Patients exhibiting trough plasma levels of ganciclovir below 0 .6 mg/L may be at higher risk of progression than patients who exhibited le vels above 0.6 mg/L.