61. Natural history and outcome of 200 outpatients with classical trigeminal neuralgia treated with carbamazepine or oxcarbazepine in a tertiary centre for neuropathic pain

Abstract

Carbamazepine (CBZ) and oxcarbazepine (OXC) are the first-choice medical treatments in patients with trigeminal neuralgia (TN). The aim of this retrospective study was to analyze the natural history of classical TN in a large cohort of patients, focusing on drug responsiveness, side effects, and changes in pain characteristics during the course of disease. We selected the last 100 consecutive patients with typical TN treated with CBZ and the last 100 with OXC. All had MRI scans and a complete neurophysiological study of trigeminal reflexes. The initial number of responders was 98% with CBZ and 94% with OXC. In a mean period of 8.6 months, 26% of responders to CBZ incurred in undesired effects leading to interruption of treatment or a dosage reduction to an unsatisfactory level. In a mean period of 13 months, the same occurred to 18% of responders to OXC. We found that the worsening of pain with time and the development of late resistance occurred in a small minority of patients. CBZ and OXC were efficacious in a large majority of patients, but the side effects caused withdrawal from treatment in an important percentage of patients, suggesting the opportunity to develop a drug better tolerated.