Читать книгу Current Concepts in Movement Disorder Management - Группа авторов - Страница 70

Primidone is an anticonvulsant that is metabolized to phenylethylmalonamide (PEMA) and phenobarbital. Several studies found that primidone effectively reduced the limb tremor in ET, using doses from 50 to 1,000 mg/day. A variety of side effects have been described at treatment initiation (sedation, drowsiness, nausea). In addition to propranolol, primidone is considered the other first-line treatment for ET, the choice between the two depends on concurrent medical conditions and potential side effects. Unfortunately, both primidone and propranolol tend to lose efficacy over time, and in addition, their use is limited, particularly among the elderly (>70 years), due to interactions with medications commonly used in these age group (e.g., digoxin, calcium channel blockers, and antiarrhythmics) [18–20]. Other anticonvulsants (topiramate at doses of 25–400 mg daily in two administrations, zonisamide, gabapentin, and phenobarbital) have been suggested as potentially useful agents for the treatment of ET, usually well tolerated, but less effective [19, 20]. Among benzodiazepines, alprazolam and clonazepam may also be considered with caution due to their abuse potential and possible withdrawal symptoms following abrupt discontinuation [18].