Intravenous dilevalol in the treatment of severe hypertension.

Dilevalol, the stereoisomer of labetalol, was given in repeated incremental intravenous bolus injections to 10 patients with severe hypertension requiring urgent blood pressure lowering. The mean cumulative dose of dilevalol was 445 +/- 165 mg. Blood pressure was reduced from 201 +/- 33/131 +/- 13 to 150 +/- 12/109 +/- 7 mm Hg (p less than 0.01) and heart rate did not change significantly. In only one patient was the study discontinued because of side effects (nausea and dizziness). There were no other clinically significant adverse reactions and no change was observed in electrocardiogram or routine biochemical and hematologic tests. Five of these patients, who achieved diastolic blood pressure of less than or equal to 105 mm Hg, participated in a subsequent outpatient phase of the study with combination of oral dilevalol with hydrochlorothiazide. Of these only one achieved good blood pressure control. We concluded that in such severely hypertensive patients intravenous dilevalol was safe and effective for the short-term lowering of blood pressure. However, long-term outpatient maintenance with this drug needs further evaluation.