[Which digitalis therapy is still justified today? (author's transl)].

Recent intoxication studies during digitalis therapy have shown that digoxin and digitoxin produce different pharmakokinetic results. The main difference is in the elimination pathways of the two substances. Whereas digoxin is almost exclusively excreted by the kidneys, digitoxin may be excreted both by the kidneys and by the intestine via the bile. New dosage guidelines have resulted from these studies. The problems of adjustment by means of instrumental parameters are presented and the need for individual dosage on the least effective dose principle is discussed.