Mezacar is indicated to control secondarily generalized tonic-clonic seizures and partial seizures. It is also used in the treatment of trigeminal neuralgia and has been tried with variable success in glossopharyngeal neuralgia and other severe pain syndromes associated with neurological disorders such as tabes dorsalis and multiple sclerosis. Another use is in the prophylaxis of manic depression (bipolar disorder) unresponsive to lithium.