Oral clonidine for rapid control of accelerated hypertension.

Thirty emergency-room patients, 15 men and 15 women, from 27 to 64 years old with diastolic blood pressures (DBP) greater than 115 mm Hg, were admitted to an open-label, oral loading trial of clonidine. At this time, their supine mean arterial pressures (MAP) averaged 150 +/- 2 mm Hg. An initial clonidine dose of 0.1 to 0.2 mg was to be followed every hour by another 0.1 mg until the DBP had been lowered to a level allowing treatment to be continued on an ambulatory basis or until a total of 0.5 mg had been given. A satisfactory response--defined as a reduction of the supine DBP to 105 mm Hg or lower if the baseline was between 115 and 135 mm Hg, or reduction of a baseline DBP greater than 135 mm Hg by at least 30 mm Hg--was achieved in all but one of the patients in an average of 118 minutes; the mean dose required was 0.26 mg. The mean reduction from the baseline MAP was 23.1 +/- 0.9%. Drug-related adverse experiences comprised drowsiness and dry mouth in 13 patients. Thereafter, 28 of the patients were chronically treated with clonidine for an average of 73 days. In 24 patients treated for at least 80 days, the daily clonidine dose averaged 0.375 mg. All the patients required concurrent diuretic therapy. A satisfactory response (as defined above) to this maintenance treatment was shown by 85% of the patients, and full blood-pressure control (supine DBP less than 95 mm Hg) was attained in 78%.(ABSTRACT TRUNCATED AT 250 WORDS)