Long-term treatment of trigeminal neuralgia with carbamazepine.

The results of treating 143 patients with trigeminal neuralgia with carbamazepine (CBZ) over a 16-year period have been reviewed. The drug was effective initially with few mild side effects in 99 patients (69%). Of these, 19 developed resistance later, i.e. between 2 months and 10 years after commencing treatment, and required alternative measures. Of the remaining 80 (56%), the drug was effective in 49 for 1-4 years and in 31 for 5-16 years. Thirty-six patients (25%) failed to respond to CBZ initially and required alternative measures, as did 8 (6%) who were intolerant of the drug. One patient developed CBZ-induced water intoxication with hyponatraemia. Subsequently hyponatraemia was excluded in 17 patients who had been taking CBZ for between 4 months and 7 years. This study has thus confirmed the efficacy of CBZ in the treatment of trigeminal neuralgia and shown that it may continue to be effective for many years.