Introduction & Objective: Sublingual captopril was shown to be a safe and effective drug to control hypertensive urgencies. However the exact time and efficacy of lowering blood pressure (BP) is a matter of interest and importance. In this study we evaluated the time and efficacy of 25 mg sublingual captopril in lowering blood pressure.

Materials & Methods: In a randomized clinical trial 101 patients (34 men, 67 women) with blood pressure of 180/110 mmHg (or more) who had no finding of major organ damage (heart – brain -eyes –renal) were studied by prescription of 25 mg sublingual captopril. Then systolic and diastolic blood pressure was measured at 5, 10, 15, 20, 25, 30, 40, 50, 60, 75, 90, 105, 120 minutes following drug administration. Data analysis was performed using paired t-test and SPSS software.

Results: The results showed that almost all the patients had some decrease in BP. After 120 minutes blood pressure dropped about 5% in 30%, and 5-30% in 70% of patients, compared to first measured BP. Maximal effect was observed in 25-30 minutes after drug administration: after 30 minutes systolic pressure dropped in 68.4% and diastolic pressure in 65.3% of patients about 5-25%. 47 patients had low response to therapy after 60 minutes, so they received another 25 mg captopril sublingual, which BP dropped in 45% of them. 19 patients were prescribed IV furosemide after 120 minutes. This group had resistant HTN and 25 cases of them were treated with ACEI previously. BP decreased gradually and not more than 30% of first BP. None of the patients encountered side effects.

Conclusion: Sublingual captopril is a good, safe, effective, available and cost effective drug, with very low side effects in treating patients with hypertensive crisis. It is recommended to use this drug instead of Nifedipine in all hypertensive patients.