Macrolide antibiotics appear to be able to enhance the oral bioavailability of digoxin by altering the gastrointestinal flora that metabolize digoxin to less active dihydro metabolites, thus leading to increased serum digoxin concentrations and possible digoxin toxicity in select patients stabilized on digoxin therapy. This interaction may be of clinical importance in up to 10% of the population. Currently, the orally administered erythromycin, clarithromycin, and roxithromycin have been implicated. Although realistically this interaction may be encountered rarely, when it does occur, it can be of clinical significance.