[Influence of various gastrointestinal disorders and dysproteinemia on the determination of blood digitalis by means of radioimmunoassay].

Radioimmunologically determined digoxin and beta methyl digoxin values were the same in cardiopaths with and without clinical and instrumental changes referable to chronic cirrhosis or hepatitis. Lower values, however, were noted when gastroenteric disturbances were present. This was especially true of beta methyl digoxin in subjects with hyperkinetic-hyperchlorhydric syndromes due to depressed gastric pH, with a consequent inhibition of beta methyl digoxin absorption, presumably caused by lability of the molecule as a result of methylation of the terminal digitoxose group.