Cardiac glycosides.

Despite continuous controversy associated with a variety of aspects of the pharmacology of the cardiac glycosides, it appears that these agents will continue to be widely used in the future. Current methods for the measurement of digoxin are unreliable and allow measurement of both cardioinactive metabolites of digoxin and endogenous digoxin-like substances. As a result, the therapeutic monitoring of digoxin concentrations should, for the most part, be limited to an assessment of patient compliance and confirmation of a clinical impression of drug toxicity.