Carbamazepine is widely used to manage of seizures and symptomatic treatment of trigeminal neuralgia and central pain.

We experienced two cases of exceedingly rare but potentially fatal side effects following carbamazepine administration. One traumatic brain injured patient developed pancytopenia 3 weeks after beginning to take carbamazepine for prophylactic management of seizure and the other C6 incomplete spinal cord injured patient receiving carbamazepine for the management of central pain sequentially developed syndrome of inappropriate secretion of antidiuretic hormone (SIADH) 1 week after administration.

Because of more frequent indications of carbamazepine, these side effects must be borne in mind and cautious administration will be desirable.