New applications of eslicarbazepine and eslicarbazepine acetate in the treatment of intractable conditions, selected from epilepsy, central and peripheric nervous system disorders, affective disorders, schizoaffective disorders, bipolar disorders, attention disorders, anxiety disorders, neurophatic pain and neuropathic pain- related disorders, sensorimotor disorders, vestibular disorders, and nervous function alterations in degenerative and post-ischemic diseases. Preferably the intractable condition is, at least in part, caused by an overexpression of P-gp or MRP.