Comparison between isosorbide dinitrate aerosol and nifedipine in the treatment of hypertensive emergencies.

Background: Nitric oxide donors have been used in the management of hypertensive emergencies (HE). Isosorbide dinitrate aerosol (ISA) is a nitric oxide fast-acting donor. The aim of this study is to compare the efficacy of ISA and nifedipine in the treatment of HE.
Methods: Sixty adult patients with an HE were randomised to receive either ISA (2.5 mg) or nifedipine (10 mg). Patients were given an electrocardiogram (ECG) immediately prior, and 30 min after administering the medication. Blood pressure (BP) was measured every 5 min for the first 30 min, and then every 30 min for a period of 6 h.
Results: Blood pressure values for all patients in the ISA group decreased significantly (187 +/- 13/121 +/- 6 to 153 +/- 15/92.3 +/- 7.6 mmHg, P < 0.005). Two of the patients in this group had angor pectoris with evidence of subepicardial ischaemia as seen in the first ECG, both of which disappeared with the drug. Heart rate decreased by 14%. Similarly, all patients in the nifedipine group had significant decreases in BP (190 +/- 23/115 +/- 7 to 153 +/- 26/86 +/- 6 mm Hg, P < 0.005). Their first ECG was normal. Two patients suffered angor pectoris after nifedipine, with subepicardial ischaemia registering in the second ECG. Heart rate increased 11.9% in this group. During the follow-up period, no clinically significant side effects or cases of rebound hypertension were observed in the ISA group, whereas in the nifedipine group, eight patients reported having headaches and four others rebound hypertension.
Conclusion: Our results show a favourable effect of ISA in the treatment of HE.