There is important evidence in favor of the use of angiotensin-converting enzyme inhibitors for treating hypertensive urgencies , compared with calcium channel blockers , considering the better effectiveness and the lower frequency of adverse effects ( like headache and flushing )
CONTEXT AND OBJECTIVE Hypertensive urgencies are defined as severe elevations in blood pressure without evidence of acute or progressive target-organ damage .
The need for treatment is considered urgent but allows for slow control using oral or sublingual drugs .
If the increase in blood pressure is not associated with risk to life or acute target-organ damage , blood pressure control must be implemented slowly over 24 hours .
For hypertensive urgencies , it is not known which class of antihypertensive drug provides the best results and there is controversy regarding when to use antihypertensive drugs and which ones to use in these situations .
The aim of this review was to assess the effectiveness and safety of oral drugs for hypertensive urgencies .
Efficacy of captopril and nifedipine in black and white patients with hypertensive crisis
We examined the antihypertensive efficacy of : ( 1 ) sublingual-oral single doses of captopril ( 25 mg ) and nifedipine-capsules ( 10 mg ) in 9 + 9 white patients and in 9 + 8 black patients with hypertensive crisis ; and ( 2 ) a single oral dose of the slow-acting preparation of nifedipine-retard  ( 20 mg ) in another 10 black patients . Blood pressure ( BP ) was assessed at 10 min intervals for 6 h after administration . After 6 h , the BP falls induced by these drugs were still significantly lower than the baseline placebo values . Hypotensive effect of nifedipine-capsules was established more rapidly than that of captopril in both white and black patients , and of nifedipine-retard in black patients . Considering the area under the curve of BP values during the 6-h treatment , the overall hypotensive effect of nifedipine-capsules was similar to captopril in white patients , but significantly more pronounced than captopril and nifedipine-retard in black patients . In white patients similar maximal drops of BP ( mean ± s.e.m . ) were obtained with nifedipine-capsules ( 71 ± 4/52 ± 4 mm Hg ) and with captopril ( 69 ± 4/50 ± 3 mm Hg ) . In black patients the maximal drop of BP of nifedipine-capsules ( 70 ± 4/52 ± 4 mm Hg ) was greater ( P < 0.02 ) than that of captopril ( 48 ± 4/32 ± 3 mm hg ) but similar to that of nifedipine-retard ( 71 ± 4/49 ± 4 mm hg ) . however , in contrast to nifedipine-capsules and captopril , nifedipine-retard produced a slower drop in bp . the time of peak drop in bp of both nifedipine-capsules and captopril occurred within the first 2 h whereas with nifedipine-retard it occurred only between 4 and 6 h after administration . fewer patients reported side effects with nifedipine-retard as compared with the other two preparations . we conclude that single doses of captopril and nifedipine  reduces bp for at least 6 h in both white and black patients with hypertensive crisis , but nifedipine is more potent than captopril in black patients . the slow release form of nifedipine-retard  effectively and safely lowers bp while achieving a rapid enough effect without the critical rapid falls in bp that occur with nifedipine-capsules
There is important evidence in favor of the use of angiotensin-converting enzyme inhibitors for treating hypertensive urgencies , compared with calcium channel blockers , considering the better effectiveness and the lower frequency of adverse effects ( like headache and flushing )
CONTEXT AND OBJECTIVE Hypertensive urgencies are defined as severe elevations in blood pressure without evidence of acute or progressive target-organ damage .
The need for treatment is considered urgent but allows for slow control using oral or sublingual drugs .
If the increase in blood pressure is not associated with risk to life or acute target-organ damage , blood pressure control must be implemented slowly over 24 hours .
For hypertensive urgencies , it is not known which class of antihypertensive drug provides the best results and there is controversy regarding when to use antihypertensive drugs and which ones to use in these situations .
The aim of this review was to assess the effectiveness and safety of oral drugs for hypertensive urgencies .