Unstable angina: buccal nitroglycerin caused fewer headaches than intravenous.

Clinical bottom line (level 1b)

  1. Patients with unstable angina who had buccal nitroglycerin rather than intravenous, had fewer side effects (NNT = 3 at 7 days) .
  2. There was no clear difference on the frequency of painful episodes or the number of patients requiring emergency revascularisation.
Dellborg et al: European Journal of Clinical Pharmacology 1991; 41: 5-9
Expires July 2003

The study

Unblinded concealed randomised trial without intention-to-treat
Setting: university hospital, Sweden

29 patients (aged range 39 to 74 years; mean 60, 62% male) unstable angina (defined as angina of recent onset or a sudden change in a previously stable pattern, with chest pain occurring at rest or on a low level of exercise)

Excluded if
  • >75 years old
  • acute MI within one month
  • initial blood pressure <110/70 mmHg
  • heart rate >120
  • bundle branch block
  • contraindication to treatment with metoprolol or aspirin
  • suspected alcohol abuse or other reason to suspect poor compliance


    • Control Group: (n = 16, 16 analysed): iv nitroglycerin 0.25 µ g/kg/min initially and increased every 15 minutes by 0.25 µ g until relief of pain or haemodynamic intolerance (heart rate >120, blood pressure <100/50) for 24 hours. The tablet was changed every 4 hours.
    Experimental Group: (n = 13, 13 analysed): buccal nitroglycerin 2.5 mg initially and increased every 15 minutes by 2.5 mg until relief of pain or haemodynamic intolerance for 24 hours
    All patients had aspirin 125 mg po once daily, and metoprolol 100-200 mg po once daily.
    100% followed for 7 days
    Outcome notes:
    • side effects : headache, haemodynamic intolerance, nausea

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    emergency CABG or PTCA 7 days 4
    (25.0%)    		 1
    (7.69%)    		 69%
    (-143% to 96%)    		 17.3%
    (-8.38% to 43.0%)    		 6
    (NNT = 2 to infinity;
    NNH = 12 to infinity)
    side effects 7 days 12
    (75.0%)    		 5
    (38.5%)    		 49%
    (-8% to 76%)    		 36.5%
    (2.63% to 70.4%)    		 3
    (1 to 38)

    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    pain episodes per 24 hours 2.8
    (2.0)     		3.8
    (3.3)     		1.0
    (-1.0 to 3.0)

    Comments

    1. The study is too small and too short to exclude potential harm from using buccal nitroglycerin, although most compounds have not been shown to be harmful.

    Citation

    1. Dellborg M, Gustaffson G, Swedberg K: Buccal versus intravenous nitroglycerin in unstable angina pectoris. European Journal of Clinical Pharmacology 1991; 41: 5-9
    Search Terms: angin* in Cochrane
    Contributor: Chris Ball and Clare Wotton, July 2000
    Reviewer: Dwight Peretz

    Clinical Question.
    Patient unstable angina
    Intervention or Exposure buccal nitrates, GTN
    Comparison intravenous GTN
    Outcome death, pain, side effects