cardiac glycoside
3 interactions related to cardiac glycoside
digoxin + st. john's wort
St. John's wort induces intestinal P-glycoprotein, increasing efflux of digoxin and reducing its absorption. Controlled studies show digoxin AUC falls roughly 25% and peak concentrations around 30-36% after two weeks of St. John's wort, potentially producing therapeutic failure in rate control or heart failure management.
digoxin + hawthorn
Hawthorn (Crataegus) has digoxin-like positive inotropic activity, may modulate P-glycoprotein efflux, and can interfere with serum digoxin immunoassays. Concurrent use raises the risk of additive cardiac effects and erroneous digoxin level readings even though formal pharmacokinetic studies show little change in digoxin AUC.
digoxin + licorice
Glycyrrhizin in licorice inhibits 11-beta-hydroxysteroid dehydrogenase type 2, mimicking aldosterone excess and causing sodium retention and potassium wasting. The resulting hypokalemia sensitizes the myocardium to digoxin and can trigger toxicity (arrhythmias, heart block) even at therapeutic serum digoxin levels.