Evaluating the Transporter Protein Inhibitor Probenecid In Patients With Epilepsy
Status:
Terminated
Trial end date:
2011-06-01
Target enrollment:
Participant gender:
Summary
The study is being done to understand why some patients with epilepsy (disease of recurrence
of seizures) do not respond very well to drug treatment with anticonvulsants.
Despite the availability of many anticonvulsants, about 30% of patients with epilepsy are
resistant to them. The cause of the resistance is not clear, but one of the reasons could be
an increased amount of proteins in the cells of the body called transporter proteins.
Transporter proteins are a group of proteins that help to defend the body against toxins,
including drugs, by pumping them out of the cells. Studies have shown that the number of
transporter proteins is higher in the parts of the brain that trigger seizures when compared
to other parts of the brain.
Studies in animals have shown that taking an anticonvulsant with an inhibitor (meaning "to
stop" or "to reduce") of a transporter protein can increase the concentration of that
anticonvulsant inside the brain cells. The main purpose of the study is to determine if
taking an anticonvulsant and a transporter protein inhibitor will change the brain
concentration of the anticonvulsant.
In this study, a single dose of phenytoin (Dilantin® is a brand name anticonvulsant which has
phenytoin as its active ingredient), a commonly used anticonvulsant, will be given once by
itself, and then will be given a separate time with a single (i.e. one time only) dose of
probenecid. Probenecid, a medicine used commonly to treat gout (a disease of increased uric
acid), is known to be an inhibitor of transporter proteins. The study will use
electroencephalogram or EEG (recording of brain wave activities) to determine if the EEG
pattern when probenecid is given, will be different from the EEG pattern when phenytoin is
given alone. This will suggest that probenecid has affected the brain concentration of
phenytoin.