Oral clonidine loading in hypertensive urgencies
R. J. Anderson, G. R. Hart, C. P. Crumpler, W. G. Reed and C. A. Matthews
The response to oral clonidine hydrochloride loading in 36 severely
hypertensive patients is presented. Each patient initially received 0.2 mg
of clonidine hydrochloride, followed by 0.1 mg each hour until a dose of
0.7 mg had been given, or the diastolic blood pressure (BP) reached a
predetermined goal (110 mm Hg or total fall of at least 20 mm Hg). Only two
patients (6%) failed to reach this goal. Supine BP in the group fell from
212 +/- 22 (SD)/139 +/- 11 (SD) mm Hg to 151 +/- 21 (SD) mm Hg at six
hours. The average dose of clonidine required was 0.45 mg and control was
maximized at five hours. The response to oral clonidine loading in the
individual patient was not predictive of the eventual dose of clonidine
necessary to achieve acceptable BP control at two weeks. Oral clonidine
loading is safe and effective in the management of "hypertensive urgencies"
and offers several advantages over parenteral antihypertensive agents in
this clinical situation.
