The Treatment of Hypertension with Hexamethonium

Abstract

Hexamethonium by subcutaneous injection in doses of 10 to 75 mg. of the ion every 8 or 12 hours produced significant reductions of arterial pressure after 50 to 100 mg. of C6 ion in normal subjects suggested that this compound produced nearly complete blockade of the sympathetic outflow to the foot'0 and was, therefore, considerably more potent than previously known vasodilator agents." The present communication outlines our experience to date with C6 in the treatment of hypertension. The dosages of hexamethonium given in this paper refer to the amount of C6 ion rather than of the salt hexamethonium dibromide. TIME-DOSE RELATIONSHIPSFollowing the intravenous administration of 5 to 50 mg. of C6 ion (9.6 to 96 mg. of hexamethonium dibromide) the cardiovascular effects of the drug appeared within two to three minutes and quickly reached a maximum within 10 minutes or less. These effects consisted of a reduction of blood pressure and increase of heart rate, both of variable degree, as well as a consistent marked postural hypotension. Following the larger doses there also was a marked increase of foot blood flow and digital skin temperature. The peak of these effects usually lasted 15 minutes after which there was a gradual waning over a period of 5 to 10 hours. The heart rate usually increased only-slightly and at times actually decreased.By the intramuscular and subcutaneous routes responses occurred at 15 to 30 minutes following injection and persisted for a period similar to that observed after intravenous administration.

A Critical Evaluation of the Hypotensive Action of Hydrallazine, Hexamethonium, Tetraethylammonium and Dibenzyline Salts in Human and Experimental Hypertension

“…On the other hand, the maintenance of hypotensive effects, which others have reported [1][2][3][4] and which were often noted in our patients, are not necessarily attributable to the action of drugs. Evaluation of long term administration must take into consideration other factors which w-ill impinge upon the patient and influence the blood pressure.9 Hospitalized hypertensive patients undergoing no specific treatment, for instance, regularly reveal a fall in blood pressure, even when malignant acceleration is present; precisely when such a decline will occur in relationship to the duration of hospitalization cannot be predicted.…”

“…In the studies of acute effects, hydrallazine chloride, hexamethonium bromide and/or tetraethylammonium chloride (TEAC) and in three patients Dibenzyline (SKF 688A), were administered on consecutive days, in the order indicated in table 3. Five readings at one-minute intervals were determined with the patient reclining.…”

Further Observations on the Effects of Autonomic Blocking Agents in Patients with Hypertension

“…In five patients whose blood pressure had been lowered to some extent by oral hydrazinophthalazine, the blood pressure was reduced to lower levels by intravenous hexamethonium than had been the case prior to hydraziinophthalazinie administration. In two patients the effect on ----... 10, except for brief periods following increases in the intake of hexamethonium. In four patients postural hypotension recurred following exercise, sweating, or diarrhea, or during very hot weather.…”

The Effect of Hexamethonium as Compared to Procaine or Metycaine Lumbar Block on the Blood Flow to the Foot of Normal Subjects 12

“…In severely hypertensive, cardiac, and debilitated patients, however, profound and probably danigerous hypotension may occur after such large doses. Therefore, in actual practice, trial doses of 5 to 10 mg. have been given to these patients before increasing the dose to maximum tolerated amounts (20).…”