Fluconazole loading dose pharmacokinetics and safety in infants

Pediatr Infect Dis J. 2011 May;30(5):375-8. doi: 10.1097/INF.0b013e318202cbb3.

Abstract

Background: Invasive candidiasis is a leading cause of morbidity and mortality in critically ill infants. Prompt administration of fluconazole and achievement of the therapeutic target (area under the curve 0 to 24 hours >400 mg*h/L) improve outcomes in candidemic patients. A loading dose of fluconazole is advised for older patients but has not been evaluated in infants. We sought to determine the pharmacokinetics and safety of a fluconazole loading dose in infants at risk for invasive fungal infection.

Methods: We enrolled 10 hospitalized infants <60 days old with suspected systemic fungal infection in this open-label study; 9 received a 25-mg/kg fluconazole loading dose followed by a maintenance dose of 12 mg/kg every 24 hours for 4 additional days. Plasma samples were obtained following the loading and steady-state doses (doses 3-5). We used a 1-compartment model to fit the data to estimate pharmacokinetic indices.

Results: Data from 57 drug concentrations obtained from 8 infants (median postnatal age, 16 days [interquartile range, 13-32] and median gestational age, 37 weeks [35-38]) showed that the median fluconazole area under the curve 0 to 24 hours (mg*h/L) in this population was 479 (347-496). Of the 8 infants who received the loading dose, 5 (63%) achieved the therapeutic target on the first day of dosing, and all infants achieved a fluconazole 24-hour trough concentration >8 μg/mL. No adverse events were thought to be related to fluconazole therapy.

Conclusions: A loading dose of fluconazole (25 mg/kg) was safe in this small cohort of young infants and achieved the therapeutic target more rapidly than traditional dosing.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antifungal Agents / administration & dosage
  • Antifungal Agents / adverse effects*
  • Antifungal Agents / pharmacokinetics*
  • Candidiasis / drug therapy*
  • Chromatography, Liquid
  • Fluconazole / administration & dosage
  • Fluconazole / adverse effects*
  • Fluconazole / pharmacokinetics*
  • Humans
  • Infant
  • Infant, Newborn
  • Plasma / chemistry
  • Tandem Mass Spectrometry

Substances

  • Antifungal Agents
  • Fluconazole