Carbamazepine is used to prevent and control seizures, especially in epileptic crisis and bipolar disorder. This medication pertains to the class of benzodiazepine that are agonists, i.e., neurotransmitter facilitators that relax like anxiolytics, sedatives (sleep aids) and anticonvulsants. In some occasions, it has been used to treat schizophrenia and trigeminal neuralgia, although it has also proven effective in the treatment of Intermittent explosive disorder (IED) and the pain provoked by thyroid gland dysfunction.
Carbamazepine is an oral anticonvulsant drug, structurally similar to the tricyclic antidepressants used in treating tonic-clonic convulsions and simple (no loss of consciousness) and complex (loss of consciousness) seizures, with or without secondary generalization. It is also effective in treating neurologic origin pains such as trigeminal neuralgia and for treating some psychiatric disorders such as manic depressive disorder and the aggressive conduct sometimes produced in senile dementia.
Multidrug resistance protein 2 (MRP2, ABCC2) is involved in the transport of antiepileptic drugs and is upregulated in the brain tissues of patients with epilepsy. Therefore, genetic variations in the MRP2 gene may affect individual drug responses to the antiepileptic agent carbamazepine.
Carbamazepine induces hepatic microsomal enzymes, affecting their metabolism and that of other compounds. Although anticonvulsant associations are used frequently when the illness is refractory to a sole drug, the interactions of carbamazepine and other anticonvulsants are complex and difficult to predict. Some anticonvulsants that interact with carbamazepine are clonzepam, ethosuximide, fosphenytoin, lamotrigine, methsuximide, phenobarbital, phensuximide, phenytoin, primidone, tiagabine, topiramate, valproic acid and zonisamide. For their part, these drugs are also hepatic metabolism inductors and can affect carbamazepine metabolism. On the other hand, gabapentin does not affect carbamazepine metabolism.
Likewise, drug inductors of isoenzyme CYP3A4 can increase carbamazepine metabolism causing subtherapeutic plasma levels. Some drugs that have been proven to reduce plasma levels of carbamazepine are pioglitazone, rifampin, rifabutin, rifapentine and troglitazone.
- Carbamazepina Normon®