Transdermal ketamine, fentanyl, clonidine, or their combination as analgesics in chronic neuropathic pain - Lauretti, Gabriela Rocha; Melazzo, Patrícia O.; Pereira, Newton Lindolfo; Defino, Helton Luiz Aparecido; Araújo, Josiele S.; Lanchote, Vera Lúcia (Postgraduat Assembly in Anestesiology-PGA56, 2002)