The anticonvulsive drug oxcarbazepine is a nicotinic acetylcholine recptor channel blocker

Abstract

Oxcarbazepine is an anticonvulsive and mood-stabilizing drug used in the treatment of some forms of epilepsy. Here, we tested the effect of the drug on the ion channel properties of the nicotinic acetylcholine receptor (AChR). Electrophysiological recordings using the single-channel recording patch-clamp technique were used to evaluate AChR function in the presence or absence of different concentrations of oxcarbazepine. The main effects caused by the drug were a concentration-dependent decrease in channel mean open time, an increase in one of the components of the mean burst duration, ôburst, concomitant with a decrease in the duration of the second ôburst component, and the appearance of a new closed-channel component. The duration of the latter remained constant in the range of concentrations tested, although its relative contribution showed concentration-dependent behavior. It is concluded that oxcarbazepine blocks the AChR channel, allowing it to reopen quickly, through a mechanism compatible with that of channel blockers