Background and aims Antiviral therapy with Valganciclovir, a relatively new but potentialtoxic oral drug, is recommended to prevent further hearing deterioration in infants with (congenital) CMV infection. Viral load monitoring can possibly beused as indicator for effective treatment.
Methods A retrospective cohort study (2005–2010) in a third level neonatal intensive care unit. Neonates ≤32 weeks of gestational age (GA) with CMV infection treated with oral Valganciclovir (30 mg/kg/day) were included. Time interval (days) to reach CMV viral load below detection level (<250 copies/ml) and assumed therapeutic level (<10.000 copies/ml) were determined. Toxicity was measured by plasma trough levels (target 0.2–1 mg/L), thrombocytopenia (< 100 × 109/L) and leukopenia (< 5 × 109/L).
Data of 6 infants, median gestational age 25+2 (range 25+1–28+4) weeks, 2 with congenital and 4 with postnatal infection, were analysed. Time interval between start of therapy and viral load below detection level was 25–54 days and below therapeutic level 10–31 days. 28/37 plasma samples were in the normal range, 3/37 above and 6/37 under the target concentration. Mild transient leukopenia (4.5 × 109/L) occurred in 1 infant. No thrombocytopenia occurred.