77446
document
Effect of increasing doses of labetalol on blood pressure , plasma renin activity and aldosterone in hypertensive patients . 1 . Four different doses of labetalol ( 150 , 300 , 600 and 900 mg/day ) were given for 1 week to each of four groups of patients with essential hypertension ( six patients for each group ) . 2 . Labetalol decreased mean blood pressure and heart rate to the same extent on the first and the seventh days of treatment . Only standing blood pressure showed a dose-dependent inhibition both in the supine and upright position . 3 . Labetalol exerted a net inhibitory effect on plasma renin activity , which was related to basal renin values and was already maximal at the lowest doses . This effect was well maintained in the supine position . This effect was well maintained in the supine position , although during standing it tended to be less evident with increasing doses . 4 . Urinary aldosterone was decreased in a dose-dependent fashion and its changes were largely independent fashion and its changes were largely independent of plasma renin activity . 5 . Neither basal values nor changes of renin and aldosterone were related to the hypotensive effect of labetalol . 6 . During labetalol treatment urinary sodium excretion fell for 2-3 days and then returned to basal values . The retentive effect of labetalol on sodium was directly related to the decrease of blood pressure , and the successive sodium escape might be explained either by the observed increase of plasma volume ( indirectly measured by packed cell volume ) or by aldosterone inhibition .
77447
Intervention_Pharmacological
labetalol
77448
Intervention_Pharmacological
labetalol
77449
Intervention_Pharmacological
Labetalol
77450
Intervention_Pharmacological
Labetalol
77451
Intervention_Pharmacological
labetalol
77452
Intervention_Pharmacological
labetalol
77453
Outcome_Physical
blood pressure
77454
Outcome_Physical
plasma renin activity
77455
Outcome_Physical
aldosterone
77456
Outcome_Physical
blood pressure
77457
Outcome_Physical
heart rate
77458
Outcome_Physical
blood pressure
77459
Outcome_Physical
plasma renin activity
77460
Outcome_Physical
Urinary aldosterone
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Outcome_Physical
basal values nor changes of renin
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Outcome_Physical
aldosterone
77463
Outcome_Physical
urinary sodium excretion fell
77464
Outcome_Physical
blood pressure
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Outcome_Physical
successive sodium escape
77466
Participant_Condition
hypertensive
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Participant_Condition
essential hypertension
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Participant_Sample-size
six