Carbamazepine is an anticonvulsant and specific analgesic used in the treatment (pain relief) of trigeminal neuralgia in cases of epilepsy. The drug appears to act by reducing polysynaptic responses and blocking the post-tetanic potentiation. This drug is very specific and can cause confusion, restlessness, and nervousness in adults and may have affects on the cardiovascular system. Side effects can be severe and should be closely monitored. The more serious include black and tarry stools, blood in the urine or stools, joint pain, darkening of urine, and nosebleeds or unusual bleeding. Carbamazepine is a white to off-white powder, practically insoluble in water and soluble in alcohol and in acetone. It molecular weight is 236.27.
Carbamazepine has anticonvulsant properties which have been found useful in the treatment of psychomotor epilepsy and as an adjunct in the treatment of partial epilepsies, when administered in conjunction with other anticonvulsant drugs to prevent the possible generalization of the epileptic discharge. A mild psychotropic effect has been observed in some patients, which seems related to the effect of the carbamazepine in psychomotor or temporal lobe epilepsy. Carbamazepine relieves or diminishes the pain associated with trigeminal neuralgia often within 24 to 48 hours. Carbamazepine given as a monotherapy or in combination with lithium or neuroleptics has been found useful in the treatment of acute mania and the prophylactic treatment of bipolar (manic-depressive) disorders. Like other tricyclic compounds, carbamazepine has a moderate anticholinergic action which is responsible for some of its adverse effects. A tolerance may develop to the action of carbamazepine after a few months of treatment and should be watched for. Carbamazepine may suppress ventricular automaticity due to its membrane-depressant effect similar to that of quinidine and procainamide, associated with suppression of phase 4 depolarization of the heart muscle fibre. A number of investigators have reported a deterioration of EEG abnormalities with regard to focal alterations and a higher incidence of records with nil beta activity during carbamazepine-combined treatment.
Carbamazepine is used to treat simple and complex partial and generalized seizures, as a specific analgesic for trigeminal neuralgia, and to treat bipolar disorder. It is used alone or in combination with other antiepileptic drugs. While its exact mechanism is not totally understood, it is thought that carbamazepine blocks polysynaptic responses in nerve cells of the brain. Carbamazepine (CBZ) is a widely used drug in neurology and psychiatry. CBZ was originally introduced as an anticonvulsant and nowadays is used as a first-line drug in patients with localization-related epilepsies. There is good evidence that CBZ is effective in the management of acute mania and prophylaxis of bipolar disorder, and it might have some benefit in the treatment of drug-resistant depression. It is also used in patients with chronic neuralgic facial pain and headaches. The definite modes of action remain unclear in these diverging manifold CBZ usages, as do the causes for the cerebral side effects of the drug (drowsiness, vertigo etc.). There are only single reports on CBZ affecting cerebral metabolism measured with positron emission tomography (PET).