What happens when you take digoxin with hawthorn?
Digoxin is a narrow-therapeutic-index cardiac glycoside, historically derived from the foxglove plant. It is used to slow the ventricular rate in atrial fibrillation and to give modest contractile support in heart failure. Because even small swings in its blood level can move a patient from a sub-therapeutic to a toxic range, anything that interferes with its measurement or adds to its cardiac effects deserves attention.
Hawthorn (Crataegus oxyacantha or Crataegus monogyna) is a herb traditionally used for cardiac symptoms, mild heart failure, and palpitations. Here is what happens when the two are combined:
- The herb is absorbed alongside your digoxin. Hawthorn extracts contain cardiac-active compounds (flavonoids and oligomeric procyanidins) that, like digoxin, have mild positive inotropic and vasodilatory effects, though through different molecular pathways.
- Cardiac effects can stack. Both substances act on the heart's contraction and conduction. In a vulnerable heart, the effects could in principle compound, though the magnitude has not been characterized in clinical trials.
- The lab test gets confused. Hawthorn constituents are similar enough to digoxin to cross-react with common digoxin immunoassays. In laboratory testing, hawthorn shifted the reported digoxin level, meaning a measured value can read falsely high or falsely low depending on the assay used.
- Absorption itself changes little. A controlled crossover study co-administered a standardized hawthorn extract with digoxin and found no meaningful change in digoxin pharmacokinetics. The practical concern is the cardiac and the analytical interaction, not how much drug reaches your blood.
Why is this important?
Digoxin dosing is guided by serum levels, so anything that distorts those readings or adds to its cardiac effects can drive a real-world dosing error.
The main issue is monitoring. If hawthorn nudges a reported digoxin level upward, a clinician may reduce the dose and undertreat the underlying atrial fibrillation or heart failure; a falsely low reading can push the dose the other way. More specific laboratory methods such as liquid chromatography mass spectrometry can resolve the interference, but most hospital labs use immunoassays, and the clinician interpreting the result will not know it is unreliable unless the hawthorn use is disclosed.
There is also a pharmacodynamic concern. In a heart with reduced pumping function, additive contraction- and conduction-affecting effects from hawthorn could in theory contribute to a slow heart rate or arrhythmia. This effect is small and unproven in clinical trials, so it should be kept in proportion rather than treated as an emergency. Memorial Sloan Kettering's herb monograph reaches the same balanced conclusion: laboratory data suggest a plausible interaction, a small clinical study found coadministration tolerable, and the overall clinical relevance remains undetermined, so hawthorn should be used only under physician guidance.
What should you do?
The combination is manageable with coordination. Use this schedule.
Before making any change: Do not start hawthorn while on digoxin without your cardiologist's explicit approval, and do not stop either one abruptly on your own. Make a list of every hawthorn-containing product you take, including teas and combination heart-support blends, to bring to your prescriber.
Every day, if you are already taking both: Keep taking your digoxin exactly as prescribed. Watch for and report symptoms that could signal too much or too little cardiac effect, such as unusual slow or irregular heartbeat, dizziness, nausea, or visual changes. Mention hawthorn at every clinic visit and whenever blood is drawn for a digoxin level so the lab and clinician can account for it.
After a change (stopping hawthorn, or a dose review): Let your prescriber decide whether a repeat digoxin level is needed and, if a result lands in a borderline-high range, ask whether a more specific assay should be run. Review the long-term plan with your doctor or pharmacist; there is no high-quality evidence that hawthorn adds benefit on top of standard heart failure therapy, so the simplest safe path is often to leave it out.
Which specific products are affected?
Digoxin is sold as Lanoxin and Digox and as generic digoxin, in tablet and oral-solution forms. Because the interaction is pharmacodynamic and analytical rather than formulation-specific, the considerations apply equally to every form of digoxin.
On the hawthorn side, the products to watch include standardized leaf-and-flower extracts (such as the WS 1442 extract used in European studies and HeartCare-type products), hawthorn berry extract supplements, Crataegus tinctures, leaf-and-flower teas, and combination heart-support herbal blends that list hawthorn among the ingredients. Products vary widely in standardization (for example, oligomeric procyanidin or vitexin content), so two bottles both labeled hawthorn are not equivalent.
The science behind it
The evidence here is limited but consistent, which is why this is a moderate, monitoring-focused interaction rather than an absolute contraindication.
A randomized crossover pharmacokinetic study in 8 healthy volunteers (Tankanow R, et al. J Clin Pharmacol. 2003; PMID 12817526) co-administered a standardized hawthorn extract with digoxin and found no statistically significant change in digoxin pharmacokinetics, indicating the absorption-level risk is small.
The interference and shared-target concern comes from in-vitro assay and rat-cardiomyocyte laboratory work (Dasgupta A, et al. Arch Pathol Lab Med. 2010; PMID 20670141), which showed that hawthorn cross-reacts with a common digoxin immunoassay and acts on the same cardiac sodium-potassium pump that digoxin targets; the authors concluded that patients on digoxin should avoid hawthorn. Because this is laboratory and animal-cell evidence rather than a clinical outcome study, it establishes a plausible mechanism rather than a proven bedside effect. Memorial Sloan Kettering's About Herbs hawthorn monograph cites this work and likewise recommends use only under physician guidance (mskcc.org/cancer-care/integrative-medicine/herbs/hawthorn).
Frequently Asked Questions
Is it dangerous to take hawthorn with digoxin?
It is best avoided unless your cardiologist approves, but it is not a medical emergency. The principal risk is that hawthorn can distort the lab test used to monitor digoxin, which can lead to a dosing mistake, rather than a sudden toxic reaction.
Will hawthorn change how much digoxin gets into my blood?
Controlled testing found no meaningful change in digoxin absorption when hawthorn was added. The concern is its effect on cardiac monitoring and on the heart itself, not on how much drug you absorb.
Can I keep taking hawthorn if I tell my doctor?
Only if your cardiologist agrees. If they do, the key is that everyone interpreting a digoxin level knows you take hawthorn, so they can order a more specific assay if a result looks borderline.
Why does hawthorn confuse the digoxin blood test?
Hawthorn contains compounds similar enough to digoxin that they cross-react with many digoxin immunoassays, causing the reported value to read falsely high or low. More specific laboratory methods are not affected.
Should I stop my digoxin if I have been taking both?
No. Never stop digoxin abruptly. Keep taking it as prescribed and tell your prescriber about the hawthorn so they can adjust monitoring and reassess your heart status with you.
Does hawthorn add anything to my heart failure treatment?
There is no high-quality evidence that hawthorn improves outcomes on top of standard heart failure therapy, so most clinicians see little reason to accept the monitoring complication it creates.
Key takeaways
- Digoxin and hawthorn is a moderate interaction, driven by confused lab monitoring and shared cardiac effects rather than by changes in drug absorption.
- Controlled testing shows little change in digoxin levels in the blood; the real risks are additive cardiac effects and a digoxin blood test that can read falsely high or low.
- The safest approach is to avoid hawthorn while on digoxin unless your cardiologist approves it.
- Never stop digoxin abruptly. Coordinate any change with your prescriber, and always disclose hawthorn to any lab or clinician interpreting your digoxin level.