[Interaction of digoxin and quinidine].

Plasma digoxin level and digoxin excretion were studied in 5 pat. suffering from cardiovascular diseases who had to be digitalized because of acute states of congestive heart failure. One of the patients took quinidine simultaneously. In the "quinidine" patient digoxin level was elevated to the 2--2.5 fold, as compared with "control" patients. Digoxin excretion of the "quinidine" patient was slightly increased. Following the results, a reduction in digoxin dosage to half of the dose is recommended.