Use of verapamil as a potential P-glycoprotein inhibitor in a patient with refractory epilepsy.
OBJECTIVE
To describe a patient in whom we used adjunctive verapamil therapy was used for its P-glycoprotein inhibitory effects.


METHODS
Verapamil was added to the antiepileptic drug regimen of a 24-year-old woman with intractable epilepsy. The average time interval between hospitalizations for complex partial status doubled. The addition of verapamil greatly improved overall seizure control and subjective quality of life in this pharmacoresistant patient.


CONCLUSIONS
The overexpression of P-glycoprotein in the central nervous system may be one mechanism of pharmacoresistance in patients with epilepsy. The calcium-channel blocker verapamil is a known inhibitor of P-glycoprotein and may function to block P-glycoprotein-modulated efflux of antiepileptic drugs in the brain, thereby raising the intracellular concentration of antiepileptic drugs and ultimately decreasing seizure burden in patients with refractory epilepsy.


CONCLUSIONS
Verapamil may offer pharmacoresistant patients hope of improved seizure control due to its potential P-glycoprotein inhibitory effects.
College of Pharmacy, The Ohio State University, Columbus, OH, USA.
Monica A
MA
Summers
J Layne
JL
Moore
James W
JW
McAuley
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors*; D000328:Adult; D000927:Anticonvulsants / Q000494:pharmacology / Q000627:therapeutic use*; D004351:Drug Resistance; D004359:Drug Therapy, Combination; D004827:Epilepsy / Q000188:drug therapy*; D005260:Female; D006801:Humans; D014700:Verapamil / Q000494:pharmacology / Q000627:therapeutic use*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000927:Anticonvulsants; D014700:Verapamil