Increase in hematocrit by nifedipine in hypertensive patients

The hematocrit, hemoglobin, serum total protein and serum albumin concentration increased significantly following sublingual administration of nifedipine in patients with essential hypertension (p less than 0.05). The mean increase in hematocrit at 60 min after administration was 1.5%. The results suggest a decrease in plasma volume, perhaps due to diuresis and a shift of fluid from the intravascular to the extravascular space.