Hormonal and hemodynamic changes following single-dose felodipine treatment during mental stress

Mental stress induces changes in hemodynamic variables and in the plasma level of many hormones and plasma peptides. These changes can be modulated by various drugs, eg, beta-blockers. In a double-blind, placebo-controlled crossover study, the authors evaluated the hormonal and hemodynamic changes during psychological stress and the effect of felodipine 10 mg (plain tablet). Eight male volunteers participated. Heart rate, blood pressures, and stroke volume were measured by ECG, mercury sphygmomanometer, and impedance cardiography. Catecholamines and atrial natriuretic factor in plasma were measured by electrochemical and radioimmunoassay techniques. A single dose of felodipine, 10 mg, exaggerates the heart rate decreases the left ventricular ejection time and augments the plasma level increment of noradrenaline. The stress-induced changes in other variables were not influenced by felodipine treatment. In conclusion, acute felodipine treatment influences the reflex activation of the sympathetic nervous system during psychological stress. In the treatment of patients, especially patients with heart disease, these findings could be important but further investigations in patients need to be done.