The renal excretion of digitoxin in the acute and chronic cardiac patient.

The renal excretion of digitoxin was studied in cardiac patients who were (1) decompensated and (2) compensated. It was found that the renal excretion of digitoxin was not changed in patients suffering from left ventricular failure alone but diminished considerably during the first 24 hours of decompensation in patients suffering from both right and left ventricular failure. Patients who were maintained in a good state of compensation by adequate digitalization were found to excrete 30 to 40 per cent of their daily dose of digitoxin. Patients overdigitalized were found to excrete 70 or more micrograms of digitoxin a day. The maximal amount of digitoxin able to be destroyed in the body was considered to be approximately 50 gg. per day, a finding which explains why dosages in excess of 0.15 mg. almost invariably lead to overdigitalization. R ECENTLY, we have been able to determine in a direct, quantitative fashion the renal excretion of digitoxin in the rat,' rabbit and dog,2 and in normal man.3 The results left little doubt that the normal young adult, unlike the animals studied, ex-creted a considerable fraction (approximately 40 per cent) of administered digitoxin in his urine. The individual over 60 years of age on the other hand, was found to excrete digitoxin poorly, at least during the first 24 hours following its administration. These observations, however, did not yield any information concerning the renal excretion of the glycoside by the cardiac patient either (1) when he was decompensated, or (2) when he was being maintained in a state of compensation by administration of digitoxin. Renal studies, therefore, were done on such patients and the results of these studies are presented below. MIETHIODS A. Selection of Subjects and Patients 1) Normal Subjects. Nine normal middle-aged subjects (37 to 66 years) were picked purposely in order that the control data would be obtained on subjects whose age was similar to that of the cardiac patients. These patients were given 1.2 mg. of digitoxin (either by mouth or by vein) within a period of six hours. 853 Urine was collected daily for three consecutive days. Each sample was assayed separately. 2) Patients in Acute Cardiac Decompensation. Eight patients suffering from acute left ventricular failure, and eight from both left and right ventricular failure were given 1.2 mg. of digitoxin (Crystodigin) either orally or parenterally within a period of six hours and the total daily urine was collected …