Signs and symptoms of carbamazepine overdose.

Carbamazepine (CBZ) has been successfully employed in a variety of neurological and psychiatric disorders. The side-effects of CBZ treatment have been extensively studied. As little is known about the symptoms and prognosis of CBZ overdose, our objective was to identify the factors relevant to its prognosis. In a retrospective study of 427 cases, we analysed the distribution of age, sex, total CBZ dose, CBZ plasma level, frequency of symptoms and their association with outcome. In those patients who recovered, coma, somnolence, cerebellar syndrome and epileptic seizures were the most common manifestations of CBZ overdose. In fatal courses coma, epileptic seizures, respiratory depression and respiratory arrest ranked highest. Cardiac arrhythmias and other cardiovascular complications were rare. In 41 of 307 patients (13%) in whom outcome was reported, intoxication was fatal. The occurrence of seizures and CBZ doses exceeding 24 g proved to be important indicators of a fatal outcome. The course of intoxication seems to be more benign in patients aged below 15 years.