The present invention relates to an external preparation for transdermal administration, which remarkably enhances the skin permeability of 2-(4-ethyl-1-piperazinyl)-4-(4-fluorophenyl)-5,6,7,8,9,10-hexahydrocycloocta[b]pyridine (compound A). The adhesive preparation of the present invention has an adhesive layer formed on one surface of a support, and the adhesive layer contains (i) compound A or a physiologically acceptable acid addition salt thereof, (ii) an adhesive, (iii) lactic acid, and (iv) an additive containing a particular permeation enhancer, whereby remarkably superior skin permeability is provided.
