Differences in antihypertensive effect were due to potency rather than efficacy .
This synthesis accomplishes for PSDs what has already been achieved for thiazide-type diuretics and other antihypertensives and can guide the application of these underutilized medicines
BACKGROUND Potassium-sparing diuretics ( PSDs ) are valuable antihypertensives with additional benefits unrelated to control of systolic blood pressure ( SBP ) .
However , their key parameters affecting SBP and serum potassium are poorly defined , fostering underutilization .
Low-renin status in therapy-resistant hypertension: a clue to efficient treatment
Objective Therapy resistance is an enduring problem in clinical hypertension . Our aims were to estimate : ( 1 ) the contribution of a low-renin status in therapy resistance ; ( 2 ) whether such status could give a clue to more successful treatment ; and ( 3 ) the contribution by adrenal cortical adenomas and by primary aldosteronism . Setting Patients were referred from general and internal medicine practice s following written invitations and included consecutively . Participants were examined and followed-up on an outpatient basis . Design and interventions Patients were divided according to renin status . Low-renin patients were treated with an aldosterone inhibitor in a prospect i ve , r and omized , placebo-controlled , double-blind , cross-over study . Main outcome measures Prevalence of low-renin status in therapy resistance . Blood pressure and hormonal responses to specific treatment . Numbers of adrenocortical adenomas and primary aldosteronism . Results In 90 treatment-resistant hypertensive , 67 % had plasma renin activity ( PRA ) below 0.5 nmol/l per hour . Of the 60 low-renin patients , 38 were studied on a fixed combination of amiloride and hydrochlorothiazide . Three weeks ’ treatment reduced blood pressure by 31/15 mmHg compared to placebo  ( P ⩽ 0.0001 ) . Serum aldosterone and plasma renin activity increased substantially during active treatment . Through the subsequent 6–12 months of open treatment , seven patients ( 18 % ) showing an escape phenomenon had their high blood pressure effectively treated by extra amiloride . Of the 60 low-renin patients , eight had adrenal adenoma . Conclusion A low-renin status characterized two-thirds of patients with treatment-resistant hypertension , who could be treated efficiently by aldosterone inhibition . Patients with an escape phenomenon ( 18 % ) could effectively be treated by increasing the aldosterone inhibitor . Low-renin hypertensives had high prevalence of adrenocortical adenomas and primary aldosteronism
Differences in antihypertensive effect were due to potency rather than efficacy .
This synthesis accomplishes for PSDs what has already been achieved for thiazide-type diuretics and other antihypertensives and can guide the application of these underutilized medicines
BACKGROUND Potassium-sparing diuretics ( PSDs ) are valuable antihypertensives with additional benefits unrelated to control of systolic blood pressure ( SBP ) .
However , their key parameters affecting SBP and serum potassium are poorly defined , fostering underutilization .