Digoxin (drug interactions)
Digoxin is a medication commonly used to treat congestive heart failure and other heart conditions. However, it is important to be aware of potential drug interactions that can affect its efficacy and safety. Various substances, including herbal supplements and dietary components, may interact negatively with digoxin. For instance, licorice and horsetail can deplete potassium levels, posing risks for individuals taking digoxin, while St. John's wort may reduce its effectiveness. Calcium and magnesium supplements can be beneficial but should be taken at different times from digoxin to avoid impaired absorption. Additionally, high-fiber foods and certain laxatives can decrease the drug's absorption, complicating treatment. Interactions with prescription medications, such as antibiotics and diuretics, can also lead to increased digoxin levels and toxicity. Consequently, patients using digoxin should consult healthcare professionals about any supplements or medications they are considering to ensure safe and effective treatment.
Digoxin (drug interactions)
DEFINITION: A medication used for congestive heart failure and other heart conditions.
TRADE NAMES: Crystodigin, Lanoxicaps, Lanoxin
INTERACTIONS: Calcium, Eleutherococcus senticosus, ginkgo biloba, hawthorn, horsetail, licorice, magnesium, St. John’s wort, uzara, psyllium and high fiber foods, various prescription medications
Magnesium
Effect: Supplementation Possibly Helpful, but Take at a Different Time of Day
Magnesium deficiency can increase the risk of toxicity from digoxin. However, taking magnesium supplements at the same time as digoxin might impair the absorption of the drug. One should not take the magnesium supplement during the two hours before or after using digoxin.
Calcium
Effect: Supplementation Possibly Helpful
Although the evidence is quite weak, digoxin might cause a tendency toward calcium deficiency. Taking calcium supplements can be helpful.
Hawthorn
Effect: Possible Interaction
The herb hawthorn is used to treat congestive heart failure. However, it is unclear whether it is safe to combine hawthorn with digoxin. One small study failed to find any harmful interaction, but more research must be done before reliable conclusions can be drawn.
Licorice
Effect: Possible Dangerous Interaction
Licorice root can lower potassium levels in the body, which can be dangerous for a person taking digoxin. The special form of licorice known as DGL (deglycyrrhizinated licorice) is a deliberately altered form of the herb that should not affect potassium levels.
Eleutherococcus senticosus
Effect: Possible Interaction
There has been one report of an apparent elevation in digoxin levels caused by the herb Eleutherococcus senticosus (also known as Siberian ginseng). However, the details of the case suggest that the Eleutherococcus product might actually have interfered with a digoxin test rather than the digoxin levels themselves.
Horsetail
Effect: Possible Dangerous Interaction
Because horsetail can deplete the body of potassium, it may not be safe to combine this herb with digitalis drugs.
St. John’s Wort
Effect: Possible Reduction of Effectiveness of Drug
Evidence suggests that St. John’s wort may interact with digoxin, possibly requiring an increased dosage to maintain the proper effect. Conversely, persons taking St. John’s wort and whose digoxin dose is adjusted by their physician should note that suddenly stopping the herb could cause blood levels of the drug to rise dangerously high.
Uzara
Effect: Possible Harmful Effect
Uzara root (Xysmalobium undulatum) is used to treat diarrhea. It contains substances similar to digoxin and may cause false readings on tests designed to measure digoxin levels. These substances also might alter (either increase or decrease) the effectiveness of digoxin.
Other Interactions
There are other interactions to be aware of when taking digoxin. Patients should avoid taking fiber supplements containing psyllium, as these may decrease the absorption of digoxin. Similarly, high-fiber foods like oatmeal can also decrease the drug's absorption. Laxatives should also be avoided for this reason. Certain antibiotics, diuretics, and corticosteroids can increase levels of digoxin, creating issues of toxicity. Finally, antiarrhythmic drugs and some antidepressants can cause an irregular heartbeat when taken with digoxin.
Bibliography
Chiang, Jiun-Yang, et al. "Digoxin-amiodarone Combination Is Associated With Excess All-cause Mortality in Patients With Atrial Fibrillation." Scientific Reports, vol. 10., no. 4101, 5 Mar. 2020, doi.org/10.1038/s41598-020-61065-4. Accessed 10 Sept. 2024.
David, Marie Nicole. "Digoxin - StatPearls." NCBI, 19 Jan. 2023, www.ncbi.nlm.nih.gov/books/NBK556025. Accessed 10 Sept. 2024.
Gurley, B. J., et al. "Gauging the Clinical Significance of P-Glycoprotein-Mediated Herb-Drug Interactions: Comparative Effects of St. John’s Wort, Echinacea, Clarithromycin, and Rifampin on Digoxin Pharmacokinetics." Molecular Nutrition and Food Research, vol. 52, no. 7, 2008, pp. 772-779.
Mauro, V. F., et al. "Impact of Ginkgo biloba on the Pharmacokinetics of Digoxin." American Journal of Therapeutics, vol. 10, 2003, pp. 247-251.
Mueller, S. C., et al. "Effect of St John’s Wort Dose and Preparations on the Pharmacokinetics of Digoxin." Clinical Pharmacology and Therapeutics, vol. 75, 2004, pp. 546-557.
Pronsky, Z. M., and J. P. Crowe. Food Medication Interactions. 16th ed., Birchrunville, Pa.: Food-Medication Interactions, 2010.
"Taking Digoxin with Other Medicines and Herbal Supplements." NHS, 22 Mar. 2023, www.nhs.uk/medicines/digoxin/taking-digoxin-with-other-medicines-and-herbal-supplements. Accessed 10 Sept. 2024.
Tankanow, R., et al. "Interaction Study Between Digoxin and a Preparation of Hawthorn (Crataegus oxyacantha)." Journal of Clinical Pharmacology, vol. 43, 2003, pp. 637-642.
Thurmann, P. A., et al. "Interference of Uzara Glycosides in Assays of Digitalis Glycosides." International Journal of Clinical Pharmacology and Therapeutics, vol. 42, 2004, pp. 281-284.