carbamazepina

Carbamazepina, also known as carbamazepine, is an anticonvulsant and mood stabilizer used to treat epilepsy (particular partial seizures with or without secondary generalization), trigeminal neuralgia, and bipolar disorder in some cases. It is often considered when seizures or mood symptoms are not adequately controlled by other therapies or when a single drug can address multiple conditions.

The medication primarily exerts its effects by blocking voltage-gated sodium channels, which stabilizes hyperexcited nerve membranes and reduces repetitive firing. It may also influence calcium channels and neurotransmitter release. After oral administration, carbamazepina is subject to autoinduction of its hepatic metabolism, meaning its own processing accelerates over weeks, which can lower plasma levels. It is mainly metabolized in the liver by CYP3A4 to an active metabolite, carbamazepine-10,11-epoxide, contributing to both therapeutic and adverse effects. The drug is excreted in urine and feces.

Common adverse effects include dizziness, drowsiness, ataxia, nausea, and blurred vision. Serious reactions can include severe skin rashes such as Stevens-Johnson syndrome (risk is higher in certain ethnic groups), hyponatremia, leukopenia or rare agranulocytosis, and hepatotoxicity. Given its enzyme-inducing properties, carbamazepina interacts with many drugs, potentially reducing the effectiveness of oral contraceptives and anticoagulants while increasing levels of other medications. It is contraindicated in bone marrow suppression, certain porphyrias, and in combination with monoamine oxidase inhibitors; caution is required in hepatic impairment.

Pregnancy carries a risk of fetal harm, including neural tube defects; disease management may require folic acid and a careful risk-benefit assessment. It is excreted in breast milk, so breastfeeding decisions should be made with medical guidance. Monitoring includes liver enzymes, complete blood counts, and, for many patients, therapeutic drug level measurements. Dosing requires gradual titration and regular reevaluation.