Dexmedetomidine is an alpha-2 agonist commonly used during neurosurgery due to its unique
properties as a sedative and anxiolytic with minimal respiratory depression. Neurosurgical
patients frequently come to the operating room on anticonvulsant therapy with a history of
seizures. The investigators clinical experience suggests that these patients are resistant to
the sedative effects of dexmedetomidine. This effect may represent a pharmacokinetic
interaction between the anticonvulsant medications and dexmedetomidine or the higher
dexmedetomidine dose requirement could result from abnormal pharmacodynamics due to the
underlying seizure disorder. The investigators study aims to investigate the pharmacokinetic
and pharmacodynamic differences of dexmedetomidine between patients receiving and not
receiving enzyme-inducing anticonvulsant therapy and to identify a potential mechanism for
these differences.