Understanding Hawthorn and Its Uses
Hawthorn (Crataegus species) is a plant whose leaves, flowers, and berries are used to make herbal supplements [1.2.9]. Traditionally, it has been used for heart and circulatory conditions, including congestive heart failure, chest pain, and irregular heartbeat [1.4.7]. Its cardiovascular effects are believed to come from compounds like flavonoids, which may improve coronary blood flow and oxygen utilization [1.3.3]. While generally well-tolerated by most people at recommended doses, hawthorn is a powerful herb with the potential to interact with conventional medications [1.2.5, 1.3.3].
Major Drug Interactions with Hawthorn
Due to its effects on the heart and blood vessels, hawthorn's most significant interactions are with cardiovascular medications. Taking hawthorn with these drugs can either dangerously enhance their effects or lead to unpredictable outcomes [1.5.1]. It is crucial to consult a healthcare provider before using hawthorn if you take any prescription drugs [1.2.1].
Heart Medications
- Digoxin (Lanoxin): This is a moderate to major interaction. Both hawthorn and digoxin work to help the heart beat more strongly [1.4.2]. Taking them together can amplify the effects of digoxin, increasing the risk of serious side effects like irregular heart rhythms [1.4.2, 1.4.4]. Some sources strongly advise against taking hawthorn if you are on digoxin [1.2.4].
- Nitrates: This is considered a major interaction. Medications like nitroglycerin and isosorbide work by increasing blood flow to the heart [1.2.4]. Hawthorn has a similar effect, and combining them can lead to an excessive increase in blood flow, causing severe dizziness and lightheadedness [1.2.4, 1.3.1].
Blood Pressure Medications
- Beta-Blockers: Drugs like atenolol (Tenormin), metoprolol (Lopressor), and propranolol (Inderal) lower blood pressure [1.2.2, 1.5.1]. Since hawthorn can also lower blood pressure, taking it with beta-blockers might cause your blood pressure to drop to an unsafe level (hypotension) [1.5.3]. Close monitoring of blood pressure is essential if this combination is used [1.5.3].
- Calcium Channel Blockers (CCBs): Similar to beta-blockers, CCBs like diltiazem (Cardizem), nifedipine (Procardia), and amlodipine (Norvasc) are used to treat high blood pressure [1.2.2, 1.3.2]. The combination with hawthorn poses a risk of hypotension due to the additive blood-pressure-lowering effects [1.2.3, 1.3.6].
- Alpha-Blockers: Medications such as prazosin may also interact with hawthorn, leading to similar concerns about low blood pressure [1.2.1].
Medications for Erectile Dysfunction (PDE5 Inhibitors)
This is another major interaction. Drugs like sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra) can lower blood pressure [1.2.4]. Combining them with hawthorn, which also has a blood-pressure-lowering effect, could cause a significant and dangerous drop in blood pressure [1.3.1, 1.5.5].
Blood Thinners
- Anticoagulant / Antiplatelet Drugs: Some evidence suggests hawthorn might slow blood clotting [1.2.3]. Taking it alongside medications that also slow clotting, such as warfarin or aspirin, could potentially increase the risk of bruising and bleeding [1.2.3].
Hawthorn Drug Interaction Comparison Table
| Drug Class | Example Medications | Potential Interaction Effect | Severity |
|---|---|---|---|
| Cardiac Glycosides | Digoxin (Lanoxin) [1.4.2] | Increases the effects and side effects of digoxin [1.4.2]. | Moderate to Major [1.2.4] |
| Nitrates | Nitroglycerin, Isosorbide [1.2.4] | May cause excessive blood flow, leading to dizziness and lightheadedness [1.2.4]. | Major [1.2.4] |
| Beta-Blockers | Atenolol, Metoprolol, Propranolol [1.2.2] | Additive effect may cause blood pressure to drop too low (hypotension) [1.5.3]. | Moderate [1.2.4] |
| Calcium Channel Blockers | Diltiazem, Nifedipine, Amlodipine [1.2.2] | Additive effect may cause blood pressure to drop too low (hypotension) [1.2.3]. | Moderate [1.2.4] |
| PDE5 Inhibitors | Sildenafil (Viagra), Tadalafil (Cialis) [1.2.4] | May cause a significant and dangerous drop in blood pressure [1.3.1]. | Major [1.2.4] |
| Anticoagulants | Warfarin, Aspirin | May increase the risk of bleeding and bruising [1.2.3]. | Moderate [1.2.3] |
Other Considerations
Beyond prescription drugs, hawthorn may interact with other substances. It can enhance the effects of other herbs or supplements that affect the heart, such as garlic or coenzyme Q10 [1.3.2, 1.3.5]. It can also interact with drugs that cause drowsiness, like certain antihistamines or muscle relaxants, potentially increasing sedation [1.2.1].
Due to its potent effects and lack of safety data, hawthorn use should be avoided by children and women who are pregnant or breastfeeding [1.2.5]. Always keep a list of all medications and supplements you use and share it with your doctor and pharmacist before starting anything new [1.2.1].
Conclusion
So, does hawthorn interact with anything? The answer is a definitive yes. While it can offer cardiovascular benefits, its potent nature means it can cause significant and potentially dangerous interactions, particularly with heart and blood pressure medications. The risk of these interactions far outweighs potential benefits when self-prescribing. Never start, stop, or alter the dosage of any medication or supplement without consulting a qualified healthcare professional who can assess your individual health status and medication regimen [1.2.1].
For more authoritative information, you can visit the National Center for Complementary and Integrative Health (NCCIH).
