IN RECENT YEARS, numerous drugs have been introduced for the reduction of blood pressure in severe hypertension. The most potent of these, the ganglionic blocking agents, have been limited in usefulness because of the side-effects associated with parasympathetic blockade.1 This report is a clinical evaluation of guanethidine (Ismelin), a new antihypertensive agent. Synthesized by Mull and associates, guanethidine, 2 (octohydro 1 azocinyl) ethyl guanidine sulfate, has an 8-member ring which differs radically from the structure of the ganglionic blocking drugs. The evidence from animal work2 indicates that guanethidine is a potent hypotensive agent which does not interfere with ganglionic transmission and produces sympathetic blockade at a lower level by preventing release or inactivating the pressor substance at the sympathetic end-plate.
Methods and Materials
To evaluate the drug's action in man, we selected a group of 16 severe hypertensive patients, with a history of 3 to 20 years' duration.