INTRAVITREOUS AND PLASMA-CONCENTRATIONS OF GANCICLOVIR AND FOSCARNET AFTER INTRAVENOUS THERAPY IN PATIENTS WITH AIDS AND CYTOMEGALOVIRUS RETINITIS

This study evaluated intravitreous and plasma ganciclovir and foscarne t concentrations after intravenous administration in AIDS patients wit h cytomegalovirus (CMV) retinitis and retinal detachment, Undiluted vi treous samples were prospectively obtained from 60 eyes (52 patients) at the time of pars plana vitrectomy, Thirty-three plasma samples (fro m 27 patients in the initial group of 52) were obtained simultaneously during surgery on 33 eyes. High-pressure liquid chromatography showed the mean vitreous ganciclovir concentrations in patients on induction and maintenance therapy were, respectively, 4.74 +/- 1.49 mu M (n = 2 4) and 3.29 +/- 1.84 mu M (n = 30; P = .005). Simultaneous plasma ganc iclovir concentrations were less than the vitreous concentrations in 7 8% of the patients. The mean intravitreous foscarnet concentrations in patients receiving induction dosages were 189 +/- 177 mu M (n = 5) ve rsus 163 +/- 167 mu M (n = 4; P > .20) for those receiving maintenance therapy, The foscarnet vitreous plasma concentration ratio averaged 1 .43, Current drugs and doses for CMV retinitis result in borderline or progressively subtherapeutic concentrations.