HORMONAL AND HEMODYNAMIC-CHANGES FOLLOWING SINGLE-DOSE FELODIPINE TREATMENT DURING MENTAL STRESS

Mental stress induces changes in hemodynamic variables and in the plas ma level of many hormones and plasma peptides. These changes can be mo dulated by various drugs, eg, beta-blockers. In a double-blind, placeb o-controlled crossover study, the authors evaluated the hormonal and h emodynamic changes during psychological stress and the effect of felod ipine 10 mg (plain tablet). Eight male volunteers participated. Heart rate, brood pressures, and stroke volume were measured by ECG, mercury sphygmomanometer, and impedance cardiography. Catecholamines and atri al natriuretic factor in plasma were measured by electrochemical and r adioimmnuoassay techniques. A single dose of felodipine, 10 mg, exagge rates the heart rate decreases the left ventricular ejection time and augments the plasma level increment of noradrenaline. The stress-induc ed changes in other variables were not influenced by felodipine treatm ent. In conclusion, acute felodipine treatment influences the reflex a ctivation of the sympathetic nervous system during psychological stres s. In the treatment of patients, especially patients with heart diseas e, these findings could be important but further investigations in pat ients need to be done.