It is intended to provide a preventive and/or a remedy for neuropathic pain which contains as the active ingredient a compound having antagonism to histamine H3 receptor such as a compound represented by the following general formula (II) or a pharmacologically acceptable salt thereof: (II) wherein W represents a group capable of imparting an antagonistic activity and/or an agonistic activity to histamine H3 receptor when attached to the 4- or 5-position of an imidazole ring; and R<3> and R<4> are the same or different and each represents optionally substituted lower alkyl, etc.
