ENALAPRIL TREATMENT EFFECTIVENESS IN ARTERIAL HYPERTENSION ELDERLY PATIENTS WITH HYPOTENSION ORTHOSTATIC REACTION P.A. Garkaviy Therapy effectiveness and orthostatic hypotension (OH) development risk were studied in 82 elderly arterial hypertension (AH) (38 males and 44 females) average age — (62,84±5,36) years patients during enalapril treatment. Effec- tiveness of enalapril in AH treatment combined with hydrochlorothiazide if required resulted in constant control of SBP and DBP. On the 2nd week — 1st month of enalapril treatment the frequency of hypotensive orthostatic reac- tions (HOR) increases from 17 to 24 % on SBP and from 14 to 17 % on DBP, and then it decreases, and up to the 6th month of therapy it is in 21 % on SBP and in 16 % on DBP. This period of AH therapy with enalapril in elderly pa- tients requires special control for the probable HOR development and their complications. Key words: enalapril, arterial blood pressure, heart rate, arterial hyper- tension, orthostatic reactions.