Certain chemical and pharmacological properties of sodium nitroprusside, a cheap, readily available chemical, have been described. It is a powerful hypotensive agent when given intravenously to hypertensive patients. It is no more effective than the sodium thiocyanate into which it is converted when given by mouth. Prolonged infusion has proved highly effective in the treatment of hypertensive encephalopathy.

No abstract

Since the responses to "neurosympathomimetic amines" are reduced in the reserpinized animal and restored by norepinephrine administration, it was postulated that norepinephrine might also affect the development of their tachyphylaxis. We found that norepinephrine infusion restored, at least partially, certain tachyphylactic responses to amphetamine or ephedrine and fully prevented the development of tachyphylaxis to tyramine.