RT Journal
A1 Wright HN
T1 THe potency of digitalis standardized according to u. s. p. xi
JF Journal of the American Medical Association
JO Journal of the American Medical Association
YR 1939
FD March 25
VO 112
IS 12
SP 1180
OP 1180
DO 10.1001/jama.1939.02800120066022
UL http://dx.doi.org/10.1001/jama.1939.02800120066022
AB To the Editor:— 
    There appears to be a growing confusion among physicians and others with regard to the changed relationships in the standardization and dosages of digitalis preparations made according to the requirements of U. S. P. XI as compared with those of U. S. P. X.All U. S. P. digitalis preparations manufactured prior to June 1, 1936, were standardized according to U. S. P. X. Practically all clinical articles published between 1926 and 1938 are based on the administration of U. S. P. X standardized digitalis. U. S. P. X required all official digitalis preparations to be standardized on frogs by the one hour progressive dose method and to be adjusted to a toxicity of 0.006 cc. (range 0.0055-0.0065 cc.) of tincture per gram of frog or, in everyday language, the equivalent of 600 mg. (range 550-650 mg.) of standard digitalis leaf per kilogram of frog.Digitalis preparations