Hypertensive crisis: no clear benefit from 10 mg nifedipine compared with 5 mg.

Clinical bottom line (level 1b-)

  1. Patients with severe hypertension who received 10 mg nifedipine rather than 5 mg did not clearly have a larger fall in diastolic blood pressure at 4 hours.
Maharaj and van der Byl: American Heart Journal 1992; 124: 720-725
Expires August 2003

The study

Double-blinded concealed randomised trial with intention-to-treat
Setting: university hospital, South Africa

30 patients (aged range 19 to 59 years; mean 49, 100% male) with severe hypertension (resting supine diastolic 115 mmHg or more on two readings two minutes apart)

Excluded if
  • myocardial infarction or stroke within six months
  • female
  • hypertensive encephalopathy
  • severe cardiac failure


    • Control Group: (n = 15, 15 analysed): nifedipine 5 mg po (bitten then swallowed)
    Experimental Group: (n = 15, 15 analysed): nifedipine 10 mg po

    100% followed for 4 hours

    The evidence

    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    diastolic pressure (mmHg) at 4 hours 105.2
    (12.5)     		97.5
    (12.5)     		7.7
    (-1.7 to 17)

  • No significant side effects were noted.

    • Citation

    1. Maharaj B, and van der Byl K: a comparison of the acute hypotensive effects of two different doses of nifedipine. American Heart Journal 1992; 124: 720-725
    Search Terms: hyperten* and emergen* in Cochrane
    Contributor: Chris Ball and Clare Wotton, August 2000
    Reviewer:

    Clinical Question.
    Patient severe hypertension
    Intervention or Exposure 10 mg nifedipine
    Comparison 5 mg nifedipine
    Outcome diastolic blood pressure