The seeds of Strophanthus hispidus or S. Kombe. The active principle is a glucoside named strophanthin. It exists in the seeds in a strength of 8 or 10 %.
Strophanthus enters the blood and acts directly on muscular tissue as a tonic, increasing its contractile power, and, in poisonous doses, paralyzing and leaving it in a state of tetanic-like spasm, - not through the agency of the nervous mechanism, but by direct influence on the muscle itself. This tonic and stimulant action is quickly felt by the heart, receiving as it does in a short time all the blood of the body, and thus feeling the action of the whole amount of strophanthus contained in it. The beats become less frequent and the cardiac contractions strengthened.
Strophanthus resembles digitalis in its action on the heart, but it is not as lasting a stimulant, though acting more quickly. It differs from it also in not affecting the vaso-motor nerves. It is not irritating to the alimentary canal, and is not cumulative. It acts as a diuretic by increasing the supply of blood to the kidneys.
Average dose, viii.-0.5 mil.
Average dose, gr. 1/80-0.00075 Gm. 15