Pharmacology Of Carbamazepine - What You Need To Know

Carbamazepine is an anti-epileptic medication that has been used for decades to treat several neurological conditions. Although it was originally developed to treat seizures, it has many other important clinical indications. Major ones include the following, to treat seizure disorders and certain types of epilepsy, to treat trigeminal neuralgia, a condition characterized by severe facial pain, and as a mood stabilizer for people with bipolar disorder to help prevent episode of mania. Carbamazepine works by blocking voltage gated sodium channels in neurons. This stabilizes overactive neurons and prevents the rapid, repetitive electrical signals that trigger seizures and certain types of neuropathic pain. As a result, neurons become less likely to fire abnormally. Carbamazepine is well absorbed after oral administration, although absorption is relatively slow. It is metabolized in the liver, mainly by the enzyme CYP3A4, into an active metabolite called carbamazepine-10-11-epoxide. One unique feature of this drug is autoinduction, meaning it stimulates its own metabolism. Because of this, its half-life becomes shorter after a few weeks of treatment and dose adjustments may be needed. The drug and its metabolites are then eliminated mainly through the kidneys. Some common adverse effects of carbamazepine include the following dizziness and drowsiness, blurred vision, nausea and vomiting, headache, and unsteady gait. Some less common but serious side effects include upholstic anemia, low white blood cell counts, liver injury, Steven Johnson syndrome, toxic epidermal acrolysis, and low sodium levels in blood. Finally, carbamazepine is contraindicated in people with a known allergy to the drug history of bone marrow suppression or those who are taking monoamine oxidase inhibitors within the previous 14 days.