Long-term effect of etilefrine pivalate on blood pressure in man.

An open and a placebo-controlled double-blind trial were carried out to measure the effect of a long-term treatment (2-6 months) with etilefrine pivalate (K 30 052, Ep) on blood pressure of 60 patients suffering from orthostatic dysregulation. Oral administration of the agent took place once daily, each dose containing 20 mg. While the acute response to a single dose was comparatively weak, long-term administration had a marked and long-lasting effect both on systolic blood pressure (+40.3 mmHg) and blood pressure amplitude (+37.5 mmHg) (p less than 0.01). Steady state values were reached only when duration of therapy was approaching 6 months. The increase in blood pressure amplitude points to an augmentation of stroke volume, whereas heart rate was virtually unaltered. Peripheral resistance appears not to be increased since diastolic pressure was unchanged. The elevation in blood pressure amplitude was fully reversible within 9 weeks of wash-out, thus hinting at functional rather than structural (sclerotic) changes in the cardiovascular system.