Abstract
Primidone in a dosage of 100 to 1000 mg with a mean of 400 mg was orally administered to 13 patients with essential tremor, whose age ranged from 44 to 88 with a mean of 64. Clinical evaluation was based on tremor score, hand writing, and of daily life activities. Serum drug levels of primidone, phenobarbital, and phenylethylmalonamide were measured in some patients in contrast to the clinical assessments. The results obtained were as follows.
1. Primidone was effective in 10 out of 13 patients (76.9%).
2. Dose-related benefits were present under the daily dosage of 400 mg, and the initial dose of 100 mg with gradual increase of 50-100 mg each at 3-to 4-day intervals considered to be appropriate.
3. Neither primidone, phenobarbital, nor phenylethylmalonamide showed close correlation between serum concentration and effectiveness for tremor.
4. Side-effects such as dizziness, sleepiness, and nausea were occasionally encountered, which, however, were preventable by starting primidone from a low dose as mentioned above.
