Hemodynamic and endocrinological effects of a new selective alpha 1-blocking agent, terazosin, in patients with essential hypertension. Results of long-term treatment.
Thirteen patients with essential hypertension were treated with an alpha 1-adrenoceptor antagonist, terazosin (1 to 4 mg/day) for 12 months. To assess the mechanism of its antihypertensive effect, the hemodynamic and endocrinological responses to terazosin were determined before, 3, and 12 months after the administration of terazosin. Blood pressure significantly decreased within 2 weeks after the start of terazosin and its effect was sustained throughout the 12 month period. Pulse rate did not change except slight increase in the third month. The hemodynamic studies revealed that total peripheral resistance significantly decreased and cardiac output slightly increased, indicating that the antihypertensive effect of terazosin is mainly produced by its vasodilation. Blood volume and plasma volume did not change. Although plasma renin activity remained the same, plasma aldosterone significantly decreased in response to terazosin. Plasma noradrenaline increased in the third month, but returned to the baseline level in the twelfth month. Thus, terazosin monotherapy lowered blood pressure throughout one year without drug tolerance including volume expansion and/or accentuation of renin-angiotensin-aldosterone system or sympathetic function.
Tomoda
F
F
Second Department of Internal Medicine, Toyama Medical and Pharmaceutical University, Japan.
Takata
M
M
Yoshida
K
K
Yasumoto
K
K
Mikawa
M
M
Sasayama
S
S
D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D011224:Prazosin / Q000031:analogs & derivatives* / Q000627:therapeutic use; D012084:Renin-Angiotensin System / Q000187:drug effects; D013997:Time Factors
D000317:Adrenergic alpha-Antagonists; C041226:Terazosin; D009638:Norepinephrine; D011224:Prazosin