Carbamazepine (CBZ) is an irninostilbene derivative, structurally similar to the tricyclic antidepressants. Chemically. CBZ is a neutral, liposoluble compound that can easily pass the bloodlbrain barrier and other membranes in the body. Developed and marketed for the treatment of epileptic seizures and trigeminal neuralgia, CBZ has been utilized more and more frequently in the last decade to treat psychiatric disorders.
Carbamazepine was first evaluated as a potential treatment in manic depressive psychosis by Takezaki and Hanaoka (1971), and Okuma et al. (1973). In 1979, Okuma et al. performed the first double-blind trial of carbamazepine in comparison with the antipsychotic chlorpromazine in mania and found that 70% and 60% of patients improved respectively. A further placebo-controlled double-blind study replicated the antimanic properties of carbamazepine under controlled circumstances (Ballenger and Post, 1980). There have since been many studies demonstrating the efficacy of carbamazepine in treating the acute manic and depressive symptoms of bipolar disorder, as well as in prophylaxis^{[4, 5]}.

Carbamazepine is a first- generation antiepileptic drug (AED) known with the proprietary brand name of Tegretol® (Novartis, Basel) in the UK and USA. Oxcarbazepine is a second- generation AED supplied under the proprietary brand name of Trileptal® (Novartis, Basel) in the UK and USA. Eslicarbazepine is a third- generation AED sold under the proprietary brand names of Zebinix® (Eisai, Hatfield) in the UK and Aptiom® (Sunovion, Marlborough, MS) in the USA.