The prolonged treatment of hypertension with guanethidine.

Eighteen months' experience with guanethidine in the treatment of severely hypertensive patients showed it to be effective in reducing the supine blood pressure of 22 of 38 patients to less than 105 mm. Hg. Twelve patients required other antihypertensive agents than guanethidine alone. To achieve almost normal levels some orthostatic hypotension was usually produced during the first weeks of treatment. The only major side effect was diarrhea, which was easily controlled by atropine.