Clinical observations on a new antihypertensive drug, 2-(2,6-dichlorphenylamine)-2-imidazoline hydrochloride

Abstract

The drug 2-(2,6-dichlorphenylamine)-2-imidazoline hydrochloride, available as Catapres, was given to 16 patients with established hypertension. Six patients were studied for one month to detect abnormalities in carbohydrate metabolism. None were found. Ten severely hypertensive patients were maintained for from 5 to 11 months on Catapres and diuretics.In a single dose, Catapres invariably lowered the blood pressure significantly, but without producing orthostatic hypotension. The maximum effect occurred between 2 and 3 hours after ingestion of the drug. The duration of drug action was 4 to 6 hours.In long-term treatment of ten patients, Catapres, combined with a diuretic, proved to be as effective as a diuretic plus guanethidine or Aldomet, which the patients had previously been taking. A dose of 0.400 to 1.200 mg. of Catapres was equivalent to 1.5 to 2.0 Gm. of Aldomet or 50 to 100 mg. of guanethidine.The chief side effect of the drug was drowsiness, but this was not incapacitating, it did not require cessation of treatment, and it became less prominent with the passage of time. In patients who had experienced severe orthostatic hypotension on other drug regimens, the condition was considerably relieved by Catapres. No signs of toxicity were noted, as judged by carbohydrate tolerance, BUN, SGPT, alkaline phosphatase, and hematologic determinations.