Abstract
Objective
To determine the plasma and cerebrospinal fluid (CSF) levels of urapidil after i.v. administration and the effect on CSF serotonin and 5-hydroxyindoleacetic acid (5-HIAA) concentrations.
Design
Open, single-dose study.
Setting
Post-surgery following neurosurgical removal of the hypophysis (n=5) or aneurysm clipping (n=1).
Patients
6 patients, aged 32–71 years, with intact bloodbrain barrier (BBB); 1 patient was studied twice.
Interventions
Single dose of 25 mg urapidil i.v. as prophylaxis of BP increase during extubation or as treatment of hypertensive episodes.
Measurements and results
Urapidil, serotonin and 5-HIAA were measured by HPLC in CSF during 8 h after urapidil administration. Urapidil was detected in CSF as soon as 5 min after injection in 3 patients. The concentration ratio of plasma/CSF after the distribution phase was about 5∶1. No significant effect on serotonin and 5-HIAA in CSF was seen.
Conclusion
After administration of a therapeutic dose, urapidil permeates the BBB and may interact with central 5-HT1A-receptors.
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References
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Additional information
The study was performed at the Department of Anaesthesia, University of the Saarland, Homburg, Germany
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Castor, G., Schmidt, U. Urapidil permeates the intact blood-brain barrier. Intensive Care Med 20, 278–281 (1994). https://doi.org/10.1007/BF01708965
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DOI: https://doi.org/10.1007/BF01708965