-Blockers and Plasma Renin Activity in Hypertension

Stokes, Gordon S.; Weber, Michaela; Thornell, Ian R.

doi:10.1136/bmj.1.5897.60

Cited by 136 publications

(35 citation statements)

References 9 publications

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“…Four of these 11 men on timolol and two of these nine men on propranolol were black; the other 14 men were Caucasian. Three of these men on timolol and three of these nine men on propranolol had electrocardiographic evidence of left ventricular hypertrophy.…”

Section: Methodsmentioning

confidence: 99%

“…However, after five weeks of treatment, the mean cardiac output rose slightly in six patients receiving timolol, whereas the mean cardiac output decreased significantly in 11 patients receiving propranolol. Franciosa and Freis'7 also reported in another study that timolol administered for five weeks to 11 patients caused a significant decrease in mean supine systolic and diastolic blood pressure, a significant decrease in mean heart rate, and no significant change in cardiac output.…”

mentioning

confidence: 99%

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Effect of timolol versus propranolol on hypertension and hemodynamics.

Aronow¹,

Ferlinz²,

Vicario³

et al. 1976

Circulation

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SUMMARY The effect of timolol versus propranolol on hypertension, hemodynamics, and plasma renin activity was evaluated in 20 men. After two weeks of placebo, 11 men received timolol 30 to 60 mg daily, and nine men received propranolol, 240 to 480 mg daily, for five weeks in a double-blind randomized study. The 20 men then received placebo again for two weeks. Right heart catheterization was performed in all 20 patients after two weeks of the first placebo and after five weeks of timolol or propranolol. Equipotent doses of timolol and PROPRANOLOL has been found to be effective as an antihypertensive agent as a single drug and especially in combination with other drugs such as diuretics or vasodilators."'18 Timolol is a new beta-adrenergic blocking drug with no membrane stabilizing effect and with no intrinsic sympathomimetic activity which has also been found effective as an antihypertensive agent.8 10, 13,19 Franciosa and associates8 reported that equipotent doses of propranolol and timolol which caused a similar degree of inhibition of amyl nitrite induced tachycardia had similar effects on lowering blood pressure and heart rate. However, after five weeks of treatment, the mean cardiac output rose slightly in six patients receiving timolol, whereas the mean cardiac output decreased significantly in 11 patients receiving propranolol. Franciosa and Freis'7 also reported in another study that timolol administered for five weeks to 11 patients caused a significant decrease in mean supine systolic and diastolic blood pressure, a significant decrease in mean heart rate, and no significant change in cardiac output.Therefore, we performed a double-blind randomized study to evaluate the effect of timolol versus propranolol on blood pressure, heart rate, stroke index, cardiac index, systemic vascular resistance, and other hemodynamic variables. This paper presents the data in the 20 patients who completed this study. Materials and MethodsTwenty patients with diastolic hypertension were to complete this study. Twenty-three men received either timolol or propranolol. The mean age of the 20 men who completed this study was 52.7 ± 10.8 years. None of the patients had coronary heart disease, valvular heart disease, a history of cerebrovascular disease, a history of congestive heart failure, poor myocardial contractility, sinus bradycardia, bundle branch block, atrioventricular block, chronic obstructive lung disease, a history of bronchial asthma, allergic rhinitis, or peripheral vascular disease. Informed consent was obtained from all participants.propranolol were equally effective in significantly lowering supine and upright systolic and diastolic blood pressure and heart rate recorded on an outpatient basis. Equipotent doses of timolol and propranolol caused similar hemodynamic effects including similar significant depression of cardiac index. Equipotent doses of timolol and propranolol caused similar marked depression of plasma renin activity. The hypotensive action of timolol and of propranolol was unrelated to their ef...

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Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

Effect of timolol versus propranolol on hypertension and hemodynamics.

Aronow¹,

Ferlinz²,

Vicario³

et al. 1976

Circulation

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“…In the rabbit, a small acute reduction in blood pressure has been reported following the intravenous administration of pindolol (Weber, Thornell & Stokes, 1974). …”

Section: Introductionmentioning

confidence: 99%

“…Like many other f-adrenoceptor blocking drugs (see review by Simpson, 1974), pindolol is an effective anti-hypertensive drug in man (e.g. Feltham, Watson, Peel, Dunlop & Turner, 1972;Thorpe, 1972;Van Coller, 1973;Morgan, Sabto, Anavekar, Louis & Doyle, 1974;Stokes, Weber & Thornell, 1974) although a pressor response has been reported in some patients (Collins & King, 1972;Morgan, Louis, Dawborn & Doyle, 1972;WaalManning & Simpson, 1975).…”

Section: Introductionmentioning

confidence: 99%

Studies on the Cardiovascular Effects of Pindolol in Doca/Saline Hypertensive Rats

Buckinghamm

Hamilton

Robson

1977

British J Pharmacology

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1 A hypotensive response to orally administered pindolol in conscious normotensive and deoxycorticosterone acetate (DOCA)/saline hypertensive rats (DS‐rats) is described. In DS‐rats, pindolol (10‐50 μg/kg) produced a dose‐dependent fall in blood pressure and elevation of resting heart rate. 2 The hypotensive response and tachycardia produced by oral pindolol (50 μg/kg) in DS‐rats were prevented by propranolol (5 mg/kg), suggesting that pindolol's effects are mediated by β‐adrenoceptor stimulation. 3 After mecamylamine (10 mg/kg), oral pindolol (50 μg/kg) produced a further fall in blood pressure in DS‐rats, suggesting that its hypotensive effects are probably mediated in the peripheral vasculature. 4 Pretreatment with oral pindolol (10 or 50 μg/kg) resulted in a reduction of neuronally‐induced tachycardia in pithed DS‐rats; neuronally‐evoked pressor effects were also antagonized by pindolol (50 μg/kg, orally). 5 Whereas pindolol, 50 μg/kg orally or intraperitoneally, produced a marked and progressive hypotensive response of rapid onset (20 min) in DS‐rats the same dose intravenously produced a smaller response of delayed onset (80 minutes). 6 In anaesthetized DS‐rats, an equivalent degree of cardiac β‐adrenoceptor blockade was produced by pretreatment with pindolol, 50 μg/kg orally (2 h previously) or intravenously (1 h previously). 7 After administration of pindolol, 2 mg/kg intravenously, to conscious DS‐rats, the tachycardia produced by intravenous isoprenaline, 3 μg/kg, was almost abolished for the first 60 min of the study, whereas a hypotensive response to pindolol was delayed in onset (100 minutes). 8 The hypotensive response and tachycardia produced by oral pindolol, 50 μg/kg, in DS‐rats were prevented by inhibition of metabolic enzyme activity by pretreatment with Proadifen (SKF 525‐A), 80 mg/kg. 9 The results suggest that pindolol's effects on blood pressure and heart rate in the conscious DS‐rat are mediated by a metabolite(s) acting by stimulation of peripheral β‐adrenoceptors.

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“…In contrast, no correlation between renin activity and drug effect has been found by Stokes et al (1974), Geyskes et al (1975 and by Thurston et al (1978). It is noteworthy that some of the series quoted, both for and against, include patients with renal disease and some include only 'essential' hypertension.…”

Section: Methodsmentioning

confidence: 67%

Labetalol in severe and resistant hypertension.

Williams¹,

Murphy²,

Parsons³

1979

Brit J Clinical Pharma

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1 The efficacy of labetalol in the treatment of severe hypertension (diastolic > 115 mm Hg) was studied retrospectively. Ten patients were followed for more than 6 months. At 6 months, eight were well controlled and the mean dose in those was 975 mg daily. Four of these were receiving labetalol alone; two were on labetalol and diuretic only. 2 Three patients were resistant to doses to 1600, 1800 and 2400 mg daily respectively; two of these were controlled with increased doses of vasodilator drugs. In two cases labetalol had produced large falls in the standing BP while not influencing the supine BP. 3 Three other resistant patients were seen, of whom one merely required an increase in dose to 2200 mg daily and the addition of a diuretic. Both the others were elderly, had severe vascular disease, and suffered disabling postural hypotension on a dose of labetalol which did not influence the supine BP. 4 Labetalol can control severe hypertension. There remain patients whose supine BP is not influenced by a dose of labetalol which produces marked postural hypotension.

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-Blockers and Plasma Renin Activity in Hypertension

Cited by 136 publications

References 9 publications

Effect of timolol versus propranolol on hypertension and hemodynamics.

Effect of timolol versus propranolol on hypertension and hemodynamics.

Studies on the Cardiovascular Effects of Pindolol in Doca/Saline Hypertensive Rats

Labetalol in severe and resistant hypertension.

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