Horse Chestnut : Safety

by MedlinePlus

(Page 2 of 2)

Side Effects and Warnings

Unprocessed horse chestnut seeds, leaves, bark, and flowers contain esculin, which has been associated with significant toxicity and death. Symptoms found with horse chestnut poisoning may include vomiting, diarrhea, headache, confusion, weakness, muscle twitching, poor coordination, coma or paralysis. Horse chestnut seed extract (HCSE) standardized to escin content should not contain significant levels of esculin, and should not have the same risks.

Standardized HCSE is generally considered to be safe in adults at recommended doses for short periods of time. Stomach upset, muscular (calf) spasm, headache, dizziness, nausea and itching have been reported. Contact skin irritation (dermatitis) has been reported following application of HCSE to the skin.

Based on animal study, HCSE may cause lowered blood sugar. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a qualified healthcare provider, and medication adjustments may be necessary.

In theory, horse chestnut may increase the risk of bleeding due to the hydroxycoumarin content of esculin. Properly extracted HCSE should not contain esculin, and therefore should not carry this risk. However, caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. Monitoring is recommended and dosing adjustments may be necessary. There is a case report of liver toxicity associated with horse chestnut leaf that resolved after discontinuing the product. Kidney toxicity when high doses of escin were injected have been reported. Aflatoxins, considered to be cancer-causing agents, have been identified in commercial skin products containing horse chestnut, but not in HCSE.

Pregnancy and Breastfeeding

There is not enough scientific research to recommend the safe use of horse chestnut or HCSE during pregnancy and lactation. One small study of pregnant women treated with HCSE did not report serious adverse effects after two weeks.

Interactions

Interactions with Drugs

In theory, due to its esculin constituents, horse chestnut (but not horse chestnut seed extract, which when properly prepared does not contain esculin) may theoretically increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).

In theory, and based on limited animal study, horse chestnut seed extract (HCSE) may have an additive effect when taken with drugs that cause hypoglycemia (low blood sugar levels). Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare provider. Medication adjustments may be necessary.

Escin in HCSE may theoretically interfere with protein-bound drugs such as phenytoin (Dilantin®), warfarin (Coumadin®) or amiodarone (Cordarone®), although no cases are reported in the available literature.

Interactions with Herbs and Dietary Supplements

In theory, due to its esculin constituents, horse chestnut (but not horse chestnut seed extract, which when properly prepared does not contain esculin) may theoretically increase the risk of bleeding when taken with herbs or supplements that increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba , and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases. Some examples include: alfalfa, American ginseng, angelica, anise, Arnica montana , asafetida, aspen bark, bilberry, birch, black cohosh, bladderwrack, bogbean, boldo, borage seed oil, bromelain, capsicum, cat's claw, celery, chamomile, chaparral, clove, coleus, cordyceps, danshen, devil's claw, dong quai, evening primrose, fenugreek, feverfew, flaxseed/flax powder (not a concern with flaxseed oil), ginger, grapefruit juice, grapeseed, green tea, guggul, gymnestra, horseradish, licorice root, lovage root, male fern, meadowsweet, nordihydroguairetic acid (NDGA), onion, papain, Panax ginseng, parsley, passionflower, poplar, prickly Ash, propolis, quassia, red clover, reishi, Siberian ginseng, sweet clover, rue, sweet birch, sweet clover, turmeric , vitamin E, white willow, wild carrot, wild lettuce, willow, wintergreen, and yucca.

In theory, and based on limited animal study, horse chestnut seed extract may have an additive effect when taken with other herbs or supplements that may lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment. Possible examples include: Aloe vera, American ginseng, bilberry, bitter melon, burdock,fenugreek, fish oil, gymnema, marshmallow, milk thistle, Panax ginseng, rosemary, Siberian ginseng, stinging nettle and white horehound. Agents that may raise blood sugar levels include: Arginine, cocoa, and ephedra (when combined with caffeine).

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