Controlled Sequential Trials of Carbamazepine in Trigeminal Neuralgia

TIC DOULOUREUX is an often incapacitating affliction for which no completely satisfactory medical treatment has been available. While early observations that diphenylhydantoin has beneficial effects have been generally confirmed,1-4results with this drug are variable. Low doses are often ineffective, while the high dosages sometimes required for symptom control are poorly tolerated. Recently, Blom5,6and others7-13have reported that the paroxysmal pain of trigeminal neuralgia is promptly and consistently suppressed by the administration of carbamazepine (Tegretol), an iminostilbene derivative with anticonvulsant activity. Chemically, the compound is 5 carbamyl-5H-dibenz (b,f )-azepine, and, as indicated by the structural formula (Fig 1), it is related to the antidepressant imipramine, but not to the hydantoins. While results with carbamazepine in typical tic douloureux are reported to be highly promising, the benefits observed in postherpetic and atypical facial neuralgias have been minimal. No controlled clinical trials with carbamazepine have been reported.