Meningitis postquirúrgica. Características diferenciales de la meningitis aséptica post-quirúrgica

Evaluation of Meropenem Penetration into Cerebrospinal Fluid in Patients with Meningitis After Neurosurgery

OBJECTIVE

Meropenem is important for management of postneurosurgical meningitis, but the data about its penetration into cerebrospinal fluid (CSF) are inadequate. This prospective, open-label study investigated the pharmacokinetic profile of meropenem in patients with postneurosurgical meningitis, especially its CSF penetration.

METHODS

A total of 82 patients with postneurosurgical meningitis were included to receive meropenem intravenously according to a regimen of 2 g every 8 hours, 1 g every 8 hours, or 1 g every 6 hours. After infusion of 4 doses, blood and CSF samples were collected simultaneously at predefined time points. The high-performance liquid chromatography ultraviolet method was used to determine the concentration of meropenem.

RESULTS

The peak meropenem concentration in blood and CSF was 43.2 ± 5.3 and 2.4 ± 0.3 mg/L in the group who received 2 g every 8 hours; 28.9 ± 2.7 and 1.2 ± 0.2 mg/L in the group who received 1g every 8 hours; and31.5 ± 3.4 and 1.6 ± 0.2 mg/L in the group who received 1g every 6 hours. The maximal percent penetration into CSF was 17.6% ± 7.3%, 14.3% ± 1.7%, and 30.9% ± 24.2%, respectively.

CONCLUSIONS

Dosing regimens of meropenem 1 g every 6 hours and 2 g every 8 hours provided higher CSF penetration than 1 g every 8 hours. A higher dose and shorter dosing interval of meropenem may be more useful for clearance of pathogens.

Population Pharmacokinetics and Dosing Regimen Optimization of Meropenem in Cerebrospinal Fluid and Plasma in Patients with Meningitis after Neurosurgery

Meropenem is used to manage postneurosurgical meningitis, but its population pharmacokinetics (PPK) in plasma and cerebrospinal fluid (CSF) in this patient group are not well-known. Our aims were to (i) characterize meropenem PPK in plasma and CSF and (ii) recommend favorable dosing regimens in postneurosurgical meningitis patients. Eighty-two patients were enrolled to receive meropenem infusions of 2 g every 8 h (q8h), 1 g q8h, or 1 g q6h for at least 3 days. Serial blood and CSF samples were collected, and concentrations were determined and analyzed via population modeling. Probabilities of target attainment (PTA) were predicted via Monte Carlo simulations, using the target of unbound meropenem concentrations above the MICs for at least 40% of dosing intervals in plasma and at least of 50% or 100% of dosing intervals in CSF. A two-compartment model plus another CSF compartment best described the data. The central, intercentral/peripheral, and intercentral/CSF compartment clearances were 22.2 liters/h, 1.79 liters/h, and 0.01 liter/h, respectively. Distribution volumes of the central and peripheral compartments were 17.9 liters and 3.84 liters, respectively. The CSF compartment volume was fixed at 0.13 liter, with its clearance calculated by the observed drainage amount. The multiplier for the transfer from the central to the CSF compartment was 0.172. Simulation results show that the PTAs increase as infusion is prolonged and as the daily CSF drainage volume decreases. A 4-hour infusion of 2 g q8h with CSF drainage of less than 150 ml/day, which provides a PTA of >90% for MICs of ≤8 mg/liter in blood and of ≤0.5 mg/liter or 0.25 mg/liter in CSF, is recommended. (This study has been registered at ClinicalTrials.gov under identifier NCT02506686.)