[Clonidine versus propranolol in the treatment of essential tremor. A double-blind trial with a one-year follow-up].
BACKGROUND
To compare the efficacy of clonidine vs propranolol in the control of essential tremor, a double-blind randomized controlled trial with a one year follow-up was designed to obtain 80 % power and 95 % confidence level.


METHODS
The participants (186 patients with the essential tremor diagnosis) were recruited from the community, 122 (65.6 %) of these patients completed the trial. They were assessed using a Clinical-Evaluation Scale for Tremor and were examined 5 times, once at baseline and 4 times during the treatment phase. We used ANOVA with Bonferroni corrections, a p> value of 0.01 was considered significant. Dropouts due to side effects were compared using the Fisher's exact X (2) test for two tails, a p>value of 0.05 was considered statistically significant.


RESULTS
Propranolol as well as clonidine (p> = 0.005) proved to be statistically efficacious (p> = 0.0005). Propranolol was not more efficacious than clonidine (p> = 0.4). Dropouts were significantly higher in the clonidine group, 22 patients (p> = 0.006) and the most common undesirable side effect in this group was mouth dryness (in 8 patients).


CONCLUSIONS
Clonidine was useful; when both drugs were compared propranolol was not shown to be superior to clonidine. Based on the results of this study, clonidine appears to be a good option for the treatment of mild to moderate essential tremor.
Serrano-Dueñas
M
M
Neurological Service Carlos Andrade Marín Hospital, Quito, Ecuador. serranom@pi.pro.ec
D000316:Adrenergic alpha-Agonists / Q000627:therapeutic use*; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D003000:Clonidine / Q000627:therapeutic use*; D004311:Double-Blind Method; D020329:Essential Tremor / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011433:Propranolol / Q000627:therapeutic use*; D011446:Prospective Studies
D000316:Adrenergic alpha-Agonists; D000319:Adrenergic beta-Antagonists; D011433:Propranolol; D003000:Clonidine