Hemodynamic and Endocrinological Effects of a New Selective  1-Blocking Agent, Terazosin, in Patients With Essential Hypertension Results of Long-Term Treatment

Abstract

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.

Assessment of arterial ventricular coupling changes in patients under therapy with various antihypertensive agents by a non-invasive echocardiographic method

“…These agents cause peripheral vasodilatation but their effect on venous return would tend to decrease cardiac output, although long-term treatment has been shown to cause a significant peripheral vascular resistance decrease and a small cardiac output increase [14,17].…”

Modern alpha-1-adrenoblockers: influence of long-term administration on insulin resistance.

“…Считаем важным также отметить, что именно у этих групп пациентов и отмечаются наиболее часто метаболические нарушения и инсулинорезистетность. Здесь крайне важно отметить, что с приобретением уроселективности ингибиторы адренорецепторов не потеряли своих положительных свойств, но уменьшилась вероятность появления нежелательных побочных эффектов у этих сравнительно новых инструментов фармакологической коррекции [14,15]. Вполне естественно предположить, что уроселективные препараты по-прежнему должны были бы обладать существенным преимуществом при оценке полученных результатов терапии в катамнезе перед любыми средствами симптоматической терапии метаболических нарушений, тем более в случае назначения комбинированной терапии с добавлением альфа-липоевой кислоты и препаратов левокарнитина.…”

Direct Vasodilators and Sympatholytic Agents

“…138,139 Chronic exposure to terazosin has not been associated with tolerance, reflex volume expansion, or activation of the renin–angiotensin–aldosterone or sympathetic nervous systems. 140…”