Primidone

Primidone (Mysoline) is metabolized in part to phenobarbital and phenylethylmalonamide, both of which contribute to its anticonvulsant activity by enhancing GABA-mediated inhibition in the brain. It is FDA-approved for the control of grand mal, psychomotor, and focal seizures, and is also widely used off-label as a first-line treatment for essential tremor. Dosing is initiated at a low dose and titrated slowly to reduce sedation and dizziness, which are common when starting therapy; abrupt discontinuation should be avoided due to the risk of withdrawal seizures.