Strophanthin-K has an action on the heart similar to that of digitalis but it is absorbed more rapidly and is less cumulative. It is usually administered by intravenous injection or occasionally intramuscularly; subcutaneous injections may give rise to local inflammation. It acts in 5 to 15 minutes after intravenous injection, the effect lasting about 24 hours. If a digitalis preparation has been given during the previous 14 days, strophanthin-K is best avoided. The usual dose of strophanthin-K is 0-125 to 0-5 mg. by intravenous injection, repeated if necessary.