There is no RCT evidence demonstrating that antihypertensive drugs reduce mortality or morbidity in patients with hypertensive emergencies .
Furthermore , there is insufficient RCT evidence to determine which drug or drug class is most effective in reducing mortality and morbidity .
There were some minor differences in the degree of blood pressure lowering when one class of antihypertensive drug is compared to another .
However , the clinical significance is unknown .
Hypertensive emergencies occur when high blood pressure is associated with the presence of acute end-organ damage , such as hypertensive encephalopathy .
There is controversy as to when and which antihypertensive drugs to use in these situations .
First‐Line Treatment of Left Ventricular Failure Complicating Acute Myocardial Infarction: A Randomised Evaluation of Immediate Effects of Diuretic, Venodilator, Arteriodilator, and Positive Inotropic Drugs on Left Ventricular Function
A prospect i ve r and omised trial compared the immediate haemodynamic effects of intravenous diuretic ( frusemide ) , venodilator ( isosorbide dinitrate ) . arteriolar dilator ( hydralazine ) , and positive inotropie stimulation ( prenalterol ) as first-line therapy for acute left ventricular ( LV ) failure following myocardial infa rct ion . Forty-eight patients with transmural myocardial infa rct ion and a pulmonary artery occluded pressure ( PAOP ) of > 20 mm Hg were studied within 18 h of admission to a coronary care unit . Both frusemide ( -4 mm Hg : p < 0.01 ) and isosorbide dinitrate ( -6 mm Hg : p < 0.01 ) reduced LV filling pressure without change in cardiac index and heart rate . Although both hydralazine and prenalterol  increased cardiac index ( p < 0.01 ) , the reduction in LV filling pressure ( -2 mm Hg : p < 0.05 ) was less than with frusemide and isosorbide dinitrate . and was associated with an increased heart rate ( + 8 and + 13 beats min−1 : p < 0.01 ) . These data suggest that in acute heart failure following myocardial infa rct ion the four treatment modalities could be ranked in descending order of potential benefit as follows : ( a ) venodilatation ( isosorbide dinitrate )  — decrease of LV pressure/work : ( b ) diuretic therapy (frusemide)—  decrease of LV pressure/work offset by a transient pressor effect : ( c ) arteriolar dilatation ( hydralazine ) —decrease of LV pressure/work and of PAOP . but offset by tachycardia : and ( d ) positive inotropic therapy ( β1-agonist prenalterol )  — tachycardia and augmented LV afterload . Combination of the former and latter agents , because of their differing modes of action , should offer haemodynamic advantages over monotherapy and deserves further evaluation
There is no RCT evidence demonstrating that antihypertensive drugs reduce mortality or morbidity in patients with hypertensive emergencies .
Furthermore , there is insufficient RCT evidence to determine which drug or drug class is most effective in reducing mortality and morbidity .
There were some minor differences in the degree of blood pressure lowering when one class of antihypertensive drug is compared to another .
However , the clinical significance is unknown .
Hypertensive emergencies occur when high blood pressure is associated with the presence of acute end-organ damage , such as hypertensive encephalopathy .
There is controversy as to when and which antihypertensive drugs to use in these situations .