Slow elimination of mannitol from human cerebrospinal fluid.

ABSTRACT

OBJECTIVE: The rise of intracranial pressure above the pre-treatment level (rebound phenomenon) is considered, in part, a consequence of osmotherapeutics penetrating into the intracranial compartments. METHODS: The kinetics of mannitol in the ventricular CSF were studied in 10 patients with cerebrovascular stroke after a single i.v. infusion of 37.5 g over 15 min. RESULTS: Maximum mannitol CSF concentrations (mean = 51.1 mg.1-1) were reached 2-12 h after termination of the infusion. Mean t1/2CSF (18.3 h) by far exceeded t1/2S (3.71 h). AUCCSF/AUCS, as a measure of mannitol CSF penetration, ranged from 0.037 to 0.390. CONCLUSION: The slow elimination of mannitol from CSF implies a high risk of accumulation in the central nervous compartments after repeated dosing.