[Acute pharmacological test with clonidine for the tremor in patients with Parkinson disease]

Idiopathic Parkinson's disease has a prevalence of 1/1,000 and in 70-75% of these patients tremor is the commonest symptom. Of all the typical symptoms of this disease, the tremor is the most difficult to control. It is therefore necessary to seek drugs to solve this serious problem.

To evaluate the usefulness of clonidine in the acute treatment of resting and postural tremor in patients with idiopathic Parkinson's disease.

Acute pharmacological test (administration of 0.3 mg of clonidine chlorhydrate intramuscularly). The evaluation was done using a clinical protocol before administration and 30, 60, 120 and 240 minutes afterwards. Statistical comparison was done by variance analysis, taking a value of p < 0.0025 as significant. We included 28 patients (15 men and 13 women) of an average age of 66.9 years, and average duration of the disease of 5.53 years. Diagnosis followed the strict criteria of UKDDDSBB.

There was no difference in the evaluations before and after the first dose of L-dopa. For both types of tremor, from 60 minutes onwards there were significant differences, with the maximum 120 minutes after administration (p < 0.0001).

Clonidine is useful in the acute treatment of postural and intention tremor in patients with idiopathic Parkinson's disease. Its action is that of reducing the liberation of noradrenaline, synergically with the exciting dopaminergic system. It also seems to reduce the activity of spontaneous discharge at both thalamic and cortical levels.