Thirty-seven patients with severe hypertension were randomly assigned to receive 20 mg of ketanserin sublingually, 10 mg of ketanserin intravenously, or 20 mg of nifedipine sublingually. Systolic and diastolic blood pressures fell significantly after the three treatments. The maximum effects were reached 25 minutes after sublingual ketanserin (with decreases of 7.7% in systolic and 7.1% in diastolic blood pressure), six minutes after intravenous ketanserin (decreases of 9.4% and 9.6%, respectively), and 25 minutes after sublingual nifedipine (decreases of 16.9% and 15.9%, respectively). Blood pressure returned to pretreatment levels 20 minutes after intravenous ketanserin. Heart rate increased significantly in the group receiving nifedipine. No changes in plasma aldosterone, sodium, or potassium levels or in erythrocyte sodium and potassium levels were found after ketanserin. It is concluded that even intravenous ketanserin is inferior to sublingual nifedipine in the control of blood pressure.
