Natural Products

Hawthorn

Crataegus monogyna

Efficacy

• Indications with proven efficacy:
  Heart failure
• Also used for these other indications, but with no proof of efficacy:
  Angina
  Arrhythmia
  Atherosclerosis
  Mild hypertension
  Spasms (antispasmodic activity)
  To promote sleep

Security

• Risk of Drug Interactions: Moderate
• Adverse Effects: Not Frequent

What is it?

Active principles are found mainly in the leaves and flowerheads of this thorny shrub, which reaches 2 to 5 meters high, sometimes up to 7,5 meters. Its medicinal value has been known for centuries but its popularity has really soared in late 19th century in Europe as well as North America. The flowerheads, leaves and fruits were used to treat disturbances of arterial pressure and heart rhythm.

Hawthorn contains flavonoids, cardiotonic amines as well as several other active principles. Its therapeutic value in the treatment of cardiovascular diseases has been extensively studied: hawthorn appears to show strong cardiac activity. It can increase coronary blood flow, the heart's force of contraction as well as cardiac rate, making it useful in the treatment of heart failure. It should however never be used without proper medical monitoring. Hawthorn has also been shown to have several other properties: it apparently decreases uterine tone, gastric contractions and blood lipid levels. Hawthorn is available in capsules and tablets.

Warning

In 2004, Canada adopted new regulations that control the manufacturing, packaging, labeling and importing of natural health products. The new regulations also include an adverse reaction reporting system. Products that conform to the regulation's criteria are identified with a natural product number (NPN) or homeopathic medicine number (DIN-HM) and can be legally sold in Canada. This number indicates that the product meets specific criteria for safety and purity, not that it is effective for any indication.

Medicinal plants content varies naturally from plant to plant – just as fruits from the same package may vary in taste and texture. There is no standard to measure the active content of each plant. Thus, efficacy of natural products should be expected to vary from brand to brand as well as from bottle to bottle of the same brand.

For more information about the Natural Health Products Regulations, or to check if a product has been assessed, visit the Health Canada website at http://www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php.

Does it work?

There is evidence that hawthorn has beneficial effects in the treatment of heart failure. In addition, it is also used in other indications where it may be of some benefits:

• Heart failure :
  Evidence of effectiveness in this indication. The use of standardized oral extracts appear to improve cardiac output, exercise tolerance and symptoms of heart failure but does not reduce mortality. 160 to 1800 mg of a standardized dry extract of hawthorn leaf with flower extract (2 to 3% flavonoids or 18 to 20% procyanidins) is taken in 2 to 3 doses daily. Treatment must not be started by one-self, a health care provider must be involved.
• Angina; Arrhythmia; Atherosclerosis; Mild hypertension:
  Based on its recognized medicinal properties, one can expect hawthorn to be of some value in the treatment of these disorders, However, current data are insufficient to attest with certainty to its efficacy. No dosage recommendations are available.

There is insufficient reliable information to conclude that hawthorn is effective in any other indication.

Is it safe?

• Hawthorn use has been associated with several, usually mild, adverse effects: nausea, gastrointestinal disturbances, palpitations, headaches, dizziness and drowsiness. Hawthorn's toxic dose is thought to be 100 to 1000 times the therapeutic dose.
• Hawthorn use may potentiate the effect of digoxin (Lanoxintm), requiring a digoxin dose reduction. The use of nitrates and other cardiovascular drugs may interfere with hawthorn's effects. In addition, hawthorn is thought to potentiate the effects of some CNS drugs (anti-anxiety agents, antidepressants, etc.). Before taking hawthorn, check with your pharmacist to make sure that there are no drug interactions with your regular medication.
• Hawthorn is contraindicated in pregnant women because of its potential uterine activity. Since there are no safety data available concerning its use during breast-feeding, lactating women should not use hawthorn.

Clinical notes

• Hawthorn appears to be effective for symptom control of NYHA (New York Heart Association) stage I to III congestive heart failure but not to reduce mortality.

References

1. Blumethal M et al. The Complete German Commission E monographs, 1998
2. Natural Medicines Comprehensive Database, Therapeutic Research Faculty, 2007
3. Facts and Comparisons, The review of Natural Products, 2000
4. Grainger Bisset, N. Herbal Drugs and Phytopharmaceuticals, 1994
5. Passeportsanté.net. Aubépine. http://www.passeportsante.net
6. Barnes J. et Al. Herbal Medicines, 2nd edition, Pharmaceutical Press, 2002
7. Herbal Companion to AHFS DI, American Society of Health-System Pharmacists, 2001
8. Taylor J. CE: Phytomedicinals: Uses, precautions, and drug interactions. Drug Topics 2003;1:79
9. Barnes J. et Al. Herbal Interactions, The Pharmaceutical Journal 2003; volume 270