Primidone is primarily used as an anticonvulsant medication in the treatment of epilepsy, particularly for controlling generalized tonic-clonic seizures and partial seizures. It is also effective in managing essential tremor, a neurological disorder causing involuntary shaking. Primidone works by reducing excessive electrical activity in the brain, mainly through its metabolites phenobarbital and phenylethylmalonamide (PEMA), which enhance inhibitory neurotransmission. Due to its sedative effects and potential for dependence, it is typically prescribed when other antiepileptic drugs are not effective or well tolerated. It is also occasionally used off-label for certain movement disorders and anxiety-related conditions, though this is less common.