Carbamazepine is anti-epileptic agent.
It is used in the treatment of epilepsy - generalized tonic-clonic and partial seizures. Carbamazepine is not usually effective in absences (petit mal) and myoclonic seizures. Moreover, anecdotal evidence suggests that seizure exacerbation may occur in patients with atypical absences. It is indicated for the treatment of paroxysmal pain of trigeminal neuralgia. It is used in the prophylaxis of manic-depressive psychosis in patients unresponsive to lithium therapy.
It is formulated as tablets for oral route of administration.
Mechanism of action:
Carbamazepine stabilizes hyperexcited nerve membranes, inhibits repetitive neuronal discharges, and reduces synaptic propagation of excitatory impulses. It is conceivable that prevention of repetitive firing of sodium-dependent action potentials in depolarized neurons via use- and voltage-dependent blockade of sodium channels may be its main mechanism of action. Pain relief is believed to be associated with blockade of synaptic transmission in the trigeminal nucleus and seizure control with reduction of post-tetanic potentiation of synaptic transmission in the spinal cord. Carbamazepine greatly reduces or abolishes pain induced by stimulation of the infraorbital nerve and depresses thalamic potential and bulbar and polysynaptic reflexes, including the linguomandibular reflex. Whereas reduction of glutamate release and stabilization of neuronal membranes may account for the antiepileptic effects, the depressant effect on dopamine and noradrenaline turnover could be responsible for the anti-manic properties of carbamazepine.