Phenobarbital and propranolol in essential tremor: a double-blind controlled clinical trial.

In a double-blind study with Latin square design, phenobarbital (about 1.3 mg per kilogram), propranolol (about 1.7 mg per kilogram), and placebo were given orally for 1 month to 12 patients with essential tremor. By clinical evaluation, only propranolol appeared to be significantly more effective than placebo. As judged by tests of manual skill, none of the treatments significantly improved tremor. Patients' subjective evaluation and tremor amplitude measurement (by accelerometer) showed a significantly better effect of both propranolol and phenobarbital than placebo. These data suggest that phenobarbital may be a valuable alternative to propranolol in essential tremor.