Urinary excretion of free catecholamines in long-term treatment with dopaminergic agonists

Urinary excretion of free adrenaline, noradrenaline and dopamine was examined in 12 patients with active acromegaly before and during long-term therapy (6-22 months) with ergoline derivatives bromocriptine (20-30 mg daily) and lisuride (1-2 mg daily). A significant fall in noradrenaline values (4.5 +/- 0.95 (SEM) nmol/h on v.s. 15.3 +/- 3.8 nmol/h before the treatment, P less than 0.01) was found in the treated patients. Adrenaline excretion rose in most patients but the difference was not significant (1.43 +/- 0.33 nmol/h on v.s. 1.02 +/- 0.36 nmol/h before the treatment, P greater than 0.05). No significant change was seen in the dopamine excretion (71.3 +/- 9.58 nmol/h on v.s. 75.0 +/- 7.0 nmol/h before the treatment, P greater than 0.05). Our studies confirm the blood pressure lowering effect of bromocriptine and lisuride even when used on a long-term basis. This effect seems to be associated with reduced sympathetic activity.