heart failure
6 interactions related to heart failure
digoxin + hawthorn
Hawthorn (Crataegus) shares digoxin's cardiac target and can cross-react with the immunoassays used to monitor digoxin, so a serum level may read falsely high or low. Controlled testing shows little change in how much digoxin reaches the bloodstream, so the practical concerns are additive cardiac effects and confounded lab monitoring rather than altered absorption.
spironolactone + potassium
Spironolactone makes your body hold on to potassium instead of flushing it out. Adding a potassium supplement, salt substitute, or potassium-loaded diet on top of that can push blood potassium to a dangerous level.
furosemide + potassium
Furosemide is a loop diuretic that blocks the sodium-potassium-chloride cotransporter in the kidney, making it one of the most reliable causes of drug-induced low potassium (hypokalemia). Supplementation or potassium-sparing co-therapy is often needed, but adding potassium on your own — especially alongside ACE inhibitors, ARBs, or kidney impairment — can swing levels too high. The combination should always be guided by blood monitoring rather than self-dosing.
furosemide + magnesium
Furosemide blocks the Na-K-2Cl cotransporter in the loop of Henle, which removes the electrical gradient that normally helps the kidney reabsorb magnesium. This can increase urinary magnesium loss, especially with high-dose or prolonged use. In most outpatients the kidney's downstream segments compensate, so clinically meaningful hypomagnesemia is less common with loop diuretics than with thiazides; the effect is more relevant during high-dose IV diuresis, critical illness, or poor intake.
alcohol + digoxin
There is no major direct chemical clash between alcohol and digoxin, but alcohol works indirectly to make digoxin less safe. Alcohol can trigger irregular heart rhythms (so-called holiday heart) and, along with diuretics, deplete potassium and magnesium. Because digoxin has a narrow safety margin, those electrolyte shifts make the heart more sensitive to it and raise the risk of digoxin toxicity. Heavy drinking can also worsen the heart failure digoxin is meant to treat.
licorice tea + digoxin
Licorice (Glycyrrhiza glabra) contains glycyrrhizin, which inhibits the renal enzyme 11-beta-hydroxysteroid dehydrogenase type 2 and produces mineralocorticoid-like potassium loss. The resulting hypokalemia increases the heart's sensitivity to digoxin, raising the risk of digoxin toxicity and dangerous arrhythmias.