Clinical and computer-based assessment of long-term therapeutic efficacy of propranolol in essential tremor.

Despite a large number of studies demonstrating the effectiveness of propranolol in relieving essential tremor (ET) the long-term therapeutic outcome of these patients remains poorly defined. The results of a one-year follow-up study in 18 patients with mild to severe ET performed by using clinical and computer-based methods of assessment indicate that the initial therapeutic benefit of propranolol is apparently retained. However, following 3-6 months of sustained treatment a proportion of patients required an increase in daily dosage of propranolol in order to maintain adequate symptomatic control of tremor, indicating a relative decrease in tremorolytic efficacy of the drug possibly due to long-term tolerance.