Document Type : Original Article(s)


1 Associate Professor, Department of Cardiology, Najafabad Branch, Islamic Azad University, Isfahan, Iran

2 Medical Practitioner, Najafabad Branch, Islamic Azad University, Isfahan, Iran


 BACKGROUND: Hypertension (HTN) is the second leading risk factor for death and disability.
One fourth of healthcare in Eastern Europe and Central Asia is being spent on blood pressure
(BP)-related diseases. An important situation in patients with high BP is hypertensive crisis
(BP > 180/120 mmHg), which is divided to hypertensive emergency and urgency. Therefore,
here, we decided to compare the effect of captopril and clonidine in patients with hypertensive
urgencies, and their side effects.
METHODS: This was a parallel-group randomized clinical trial. Patients, who referred to
emergency ward with any symptoms of hypertensive crisis, underwent a careful history taking
and clinical examination. Individuals with systolic BP (SBP) ≥ 180 mmHg or diastolic BP (DBP)
≥ 110 mmHg with no evidence of end organ damage were randomly assigned into two
interventions, clonidine and captopril. 25% decrease in BP was considered as ideal relief.
RESULTS: Regarding the duration of response to treatment drugs, patients who received
clonidine relieved significantly faster than those who received captopril (P = 0.016). Moreover,
the frequencies of side effects such as headache, dizziness/vertigo, dry mouth, and drowsiness in
the clonidine group were significantly lower than captopril group (P < 0.05).
CONCLUSION: Patients in clonidine group relieved sooner and experienced fewer side effects.
Therefore, this study suggests clonidine as a more effective therapeutic for hypertensive urgency
compared with captopril.