The use of Nifedipine in Hypertensive Crisis

Available dose:  Nifedipine 10mg

Hypertensive urgency

• For hypertensive urgency, the initial treatment should aim for about 25% reduction in BP over 24 hours but not lower than 160/90 mmHg.
• In hypertensive urgency, the oral drugs that are proven to be effective are outlined in Table below. 
• Combination therapy is necessary and there is no role for intravenous BP lowering drugs.

Hypertensive Emergency

• In hypertensive emergency, all these patients should be admitted and the BP needs to be reduced rapidly.
• It is suggested that the BP be reduced by 25% depending on clinical scenario over 3 to 12 hours but not lower than 160/90 mmHg.

Issues with rapid reduction in BP

• Rapid reduction of BP (within minutes to hours) in asymptomatic severe hypertension or hypertensive urgencies is best avoided as it may precipitate ischaemic events.
• Oral or sublingual drugs with rapid onset of action can result in an uncontrolled BP reduction.
• Several serious side effects have been reported with the administration of sublingual fast-acting nifedipine and therefore this is no longer recommended.
• However oral nifedipine retard can be used and has been recommended as first line therapy for hypertensive urgencies.
• Following stabilization of patient’s BP, subsequent management is tailored towards achieving optimal control.

As a conclusion, Nifedipine is only recommended in hypertensive urgencies and not in hypertensive emergencies. 

References:

1) CPG on Management of Hypertension 4th Edition, 2013

2) http://www.uptodate.com/contents/evaluation-and-treatment-of-hypertensive-emergencies-in-adults?source=related_link