Plasma and Cerebrospinal Fluid Concentrations of Micafungin Administered at High Doses in Critically Ill Infants with Systemic Candidiasis: A Pooled Analysis of Two Studies

by Selleckchem | Apr 25 2023

Background: Neonates may require higher doses of micafungin than adults to reach the therapeutic effect for increased plasma clearance. Only poor and inconclusive data are available still now to support this hypothesis, especially with regard to central nervous system micafungin concentrations. To assess the pharmacokinetics of increased doses (8 to 15 mg/kg/day) of micafungin in preterm and term neonates with invasive candidiasis and to complete previously presented results, we analyzed the pharmacokinetic data on a total of 53 newborns treated with micafungin, whereby 3 of them had Candida meningitis and hydrocephalus.

Methods: Fifty-three neonates with systemic candidiasis, three of them with meningitis, were treated for at least 14 days with intravenous micafungin (Mycamine®) at a dosage ranging from 8 to 15 mg/kg/day. Plasma and cerebrospinal fluid (CSF) concentrations of micafungin were measured before the drug administration and at 1, 2, and 8 h after the end of the infusion using high-performance liquid chromatography (HPLC). Systemic exposure was assessed according to AUC0-24, plasma clearance (CL), and half-life measured in 52/53 patients, divided by chronological age.

Results and conclusions: The mean micafungin clearance is higher in neonates than in older infants (0.036 L/h/kg before 28 days of life versus 0.028 L/h/kg after 120 days). The drug half-life is shorter in neonates than in older patients (13.5 h before 28 days of life versus 14.4 h after 120 days). With doses ranging between 8 and 15 mg/kg/day, micafungin crosses the blood-brain barrier reaching therapeutic levels in CSF.

Comments：

In this study, the pharmacokinetics of micafungin were analyzed in 53 neonates with systemic candidiasis, three of whom had meningitis. The neonates received intravenous micafungin at a dosage ranging from 8 to 15 mg/kg/day for at least 14 days. Plasma and cerebrospinal fluid (CSF) concentrations of micafungin were measured before the drug administration and at 1, 2, and 8 h after the end of the infusion using high-performance liquid chromatography (HPLC). The systemic exposure to micafungin was assessed according to AUC0-24, plasma clearance (CL), and half-life measured in 52/53 patients, divided by chronological age.

The results of the study showed that neonates may require higher doses of micafungin than adults to reach therapeutic levels. The mean micafungin clearance is higher in neonates than in older infants (0.036 L/h/kg before 28 days of life versus 0.028 L/h/kg after 120 days), and the drug half-life is shorter in neonates than in older patients (13.5 h before 28 days of life versus 14.4 h after 120 days). However, with doses ranging between 8 and 15 mg/kg/day, micafungin crosses the blood-brain barrier reaching therapeutic levels in CSF.

These findings suggest that higher doses of micafungin may be necessary to achieve therapeutic levels in neonates with invasive candidiasis, especially those with meningitis. Further studies are needed to confirm these results and to evaluate the safety and efficacy of higher doses of micafungin in neonates.