Carbamazepine and Bipolar Disorder: Pharmacodynamics, Pharmacokinetics, Pharmacogenomics, and Adverse Drug Reactions- A Comprehensive Review

Bipolar disorder is a psychiatric illness characterized by episodes of mania or hypomania that oscillate with depression. In India around 1 in 150 people encounter this disorder but the majority of them remain untreated or misdiagnosed. The review focuses on the FDA-approved Carbamazepine (CBZ), a mood stabilizer for bipolar illness. Additionally, it is authorized for the management of generalized tonic-clonic seizures, complex partial temporal lobe epilepsy, and trigeminal neuralgia. It is largely metabolized in the liver by the variants of cytochrome enzymes such as CYP3A4, CYP3A5, CYP2C19, and CYP2C8. It manages to control maniac activities by modulating voltage-gated sodium channels, reducing dopamine and glutamate turnover while increasing serotonin and Gaba Aminobutyric Acid (GABA) levels through a variety of actions of synthesis and degradation. Though being used extensively for bipolar diseases, it has shown adverse effects which cause anemia, hepatitis, rashes, neural tube abnormalities, weight gain, hearing loss, and some cognitive effects. CBZ, either alone or in combination with other drugs, is effective in the maintenance treatment of bipolar disorder in naturalistic clinical settings. With the aid of Therapeutic Drug Monitoring (TDM), additional pharmacogenetic research may be required to more clearly define the effects of drug-metabolizing polymorphisms in everyday situations.