PROPRANOLOL PHARMACOKINETICS AND HEMODYNAMIC INDICES IN ANTIORTHOSTATIC HYPOKINESIA.

Purpose of the work was to study pharmacokinetics of beta adrenoblocker propranolol, and hemodynamic indices in volunteers for simulation of some effects of microgravity The study involved 8 essentially healthy subjects and the head-down tilt (-80) bedrest model reproducing the effects of microgravity (BD). This was designed as three series of investigations, i.e. before BD, on BD day-2 and on the first day of BD completion. Propranolol concentration in blood plasma was determined using high performance liquid chromatography with fluorescence detection. Hemodynamic indices including heart rate (HR), stroke volume, cardiac output, cardiac index and total peripheric resistance were measured using integral rheography; average blood pressure (BPav) Was assessed by Korotkovs method. Statistical deviations in propranolol pharmacokinetics were found in none of the three series. The most characteristic reactions to propranolol were BPav reductions in all series and HR decreases 2 hours after intake in the first and second series. These deviations were not pathologic but physiological variations typical of healthy people. Therefore, propranolol can be advised for rational pharmacotherapy of acute cardiovascular diseases in piloted space missions.