Comparative study of effects of fast release sublingual versus chewing-swallowing nifedipine on blood pressure decline in hypertension emergencies

Hypertensive emergency is one of the most important conditions in the emergency department with high mortality and morbidity if not treated effectively. Hypertensive emergency is commonly treated with sublingual nifedipine. This drug is very short acting and it may decrease blood pressure suddenly, resulting in dangerous side effects such as myocardial ischemia and sudden cardiac death. We intended to find of a safer route of administration. Therefore, we compared the rate of blood pressure decline following sublingual and chewing-swallowing routes of administration.Subjects and A quasi-experimental clinical study was performed on 160 patients with hypertensive emergency. All patients with blood pressure ≥210/125 mmHg and without sign of end organ damage were selected randomly into those receiving sublingual or chewing-swallowing 10 mg nifedipine capsules. The data collection tools consisted of an information sheet and a semi-automatic sphygmomanometer. Information sheet had two parts, the first was related to demographic data and the second part was the check list of blood pressure (systolic, diastolic, mean) and heart rate at 5, 10, 20, 30, 60 and 120 minutes after administration. All data include quantitative and qualitative were analyzed with paired comparison, t-test and Chi-square. The results of this study showed that there was significantly greater fall in the rate of blood pressure in the sublingually-treated group compared with chewing-swallowing group at 5, 10 and 20 minutes after taking 10 mg nifedipine (P = 0.04, 0.01, 0.06 respectively). There was no significant difference in diastolic blood pressure between both groups during the time of study. After 30 minutes the fall in systolic and diastolic blood pressures in both groups was similar. There was no significant difference in heart rate among both groups but there is some trend to the increase the rate. There was 23% decrease in mean basic blood pressure among the patients before and after treatment in sublingual and chewing-swallowing groups (P=0.0001). There was no significant correlation of blood pressure abatement rate in both groups as dependent variables of age, sex, positive history of risk factors and current drugs as independent variable. The chewing-swallowing route may be safer than sublingual route since it reduces pressure less rapidly during the first 20 minutes of administration.