Renal Hemodynamic Effects of Tertatolol in Essential Hypertension

Abstract

Tertatolol, a new β-blocker, and propranolol, considered a reference β-blocker, were given orally (5 and 160 mg slow release, respectively) for 15 days to two groups of patients with essential hypertension in order to compare their effects on renal hemodynamics. Systolic and diastolic blood pressure, heart rate, and erect plasma renin activity fell significantly in both groups while prostaglandin E₂ urinary excretion was unchanged. Tertatolol administration produced increases in glomerular filtration rate, as shown by inulin clearance (+8.9%; p = 0.038) and renal plasma flow, as shown by paraaminohippurate clearance (+13.0%; p = 0.007). In contrast, propranolol administration resulted in a slight decrease in glomerular filtration rate (-2.8%; not significant) and a fall in renal plasma flow (-13.4%; p < 0.001). Comparison between both treatments showed that glomerular filtration rate and renal plasma flow were higher in the patients treated with tertatolol than in those treated with propranolol whereas filtration fraction was lower, which suggests that tertatolol causes a vasodilation of the glomerular afferent arteriole. These results demonstrate that in contrast to propranolol (160 mg), and despite both drugs exhibiting a comparable antihypertensive activity, tertatolol (5 mg) does not alter but even improves renal perfusion in hypertensive patients.

Long-Term Experience with Tertatolol in Hypertension

“…Indeed, a renal function impair ment is generally observed when this treatment is intro duced and continues with long-term administration [8,9]. In contrast, this 1-year study confirms the beneficial effect of tertatolol on renal function previously observed in experimental [17,18] and short-term studies [19][20][21], Particularly, in keeping with what was reported by Ardaillou [20], the decrease in plasma creatinine level is greater the greater the initial level is. and reaches almost 20% in the upper-range subgroup.…”

Choosing the Right Dose for Beta-Blocker Treatment of Hypertension: Experience with Tertatolol

“…Tertatolol is a new ß-blocking drug of interest in anti hypertensive therapy as regards its renal hemodynamic effects with preservation or increase in renal blood flow and glomerular filtration rate [11] and its lack of adverse effects on biochemical risk factors for atherosclerosis [12]. The results of phase 1 and II studies which have led to the recommendation of a 5-mg dose of tertatolol once daily will be reviewed in this paper.…”

Hemodynamic Effects of Beta-Blockade in Hypertension

“…Furthermore, the vasodilation is more effective in the presence of an ini tial background of renal vasoconstriction, as can be observed in sustained essential hypertension, thus result ing in an absolute increase in renal plasma flow. In addi tion, the increase in glomerular filtration rate observed simultaneously with enhanced renal plasma How sug gests that the vasodilation caused by tertatolol is mainly located on the afferent side of the glomerular arterioles [23].…”

“…Following acute administration, the preserved renal plasma flow observed with tertatolol appears to be the consequence of a lack of vasoconstric tion within the kidney; this takes place in the context of a systemic vasoconstriction [20][21][22]. Following chronic administration, the preserved or increased renal plasma flow appears to be the consequence of renal vasodilation, this takes place in the context of the long-term adapta tion of vascular resistance [20][21][22][23]. Furthermore, the vasodilation is more effective in the presence of an ini tial background of renal vasoconstriction, as can be observed in sustained essential hypertension, thus result ing in an absolute increase in renal plasma flow.…”