Efficacy of an adenosine antagonist, theophylline, in essential tremor: comparison with placebo and propranolol.

Propranolol, which has long been used as the standard treatment for essential tremor, has been compared with placebo and theophylline in ten newly diagnosed patients without other, prior drug treatments. Patients were treated for four weeks with one drug, followed by placebo for four weeks, and then the second drug for the same period, in a blind cross-over trial. Tremor was quantified using the volumetric method, and was decreased significantly after one week on propranolol, 80 mg/day. Theophylline 150 mg/day reduced tremor to the same extent, although the improvement was not significant until the second week. Three patients reported side effects on propranolol. It is suggested that theophylline may be a useful alternative agent in the treatment of essential tremor, probably due to a chronic up-regulation of adenosine receptors.