Valacyclovir in the treatment of acute retinal necrosis

Background: To report the outcome of oral valacyclovir as the sole antiviral therapy for patients with acute retinal necrosis (ARN). Methods: This study reports a retrospective, interventional case series of nine consecutive patients with ten eyes with newly diagnosed ARN treated with oral valacyclovir as the sole antiviral agent. Eight patients received oral valacyclovir 2 g tid (Valtrex, GlaxoSmithKline) and one patient with impaired renal function received oral 1 g tid. The main outcome measures were response to treatment, time to initial response to treatment, time to complete resolution of retinitis, best corrected visual acuity (BCVA) at final follow-up, retinal detachment and development of recurrent or second eye disease. Results: Retinitis resolved in ten of ten (100%) affected eyes. The median time to initial detectable response was seven days and the median time to complete resolution was 21 days. A final BCVA of 20/40 or better was achieved in 6/10 (60%) of eyes. 3/10 eyes (30%) developed a retinal detachment. No patients developed either disease reactivation or second eye involvement over the course of the study (mean follow up 31 weeks, range 7 to 104 weeks). Conclusions: Treatment with oral valacyclovir as the sole antiviral therapy resulted in complete resolution of retinitis. Final BCVA and retinal detachment rate were comparable with previously reported outcomes for intravenous acyclovi

An investigation of the steady-state pharmacokinetics of oral valacyclovir in immunocompromised children.

Valacyclovir was administered to 28 immunocompromised children (ages 5-12 years) to obtain preliminary pharmacokinetic and safety information. Patients were randomized to valacyclovir regimens of 250 mg (9.4-13.3 mg/kg) or 500 mg (13.9-27.0 mg/kg) twice daily or 500 mg (13.2-21.7 mg/kg) 3 times a day. Acyclovir pharmacokinetics were evaluated at steady state. Valacyclovir was rapidly absorbed and converted to acyclovir. Mean (+/-SD) acyclovir peak concentrations from 250 mg and 500 mg valacyclovir were 4.11+/-1.41 and 5.19+/-1.96 microg/mL, respectively. Corresponding single dose area-under-curve values were 12.14+/-6.60 and 14.49+/-4.69h microg/mL. By using historical data for intravenous acyclovir as reference, the overall estimate of acyclovir bioavailability from valacyclovir was 48%, 2- to 4-fold greater than for oral acyclovir. In general, adverse events were not attributable to valacyclovir and were consistent with disease-related expectations and concomitant therapies. Dosage options for using valacyclovir in children are discussed