Horse chestnut: Dosage. Interactions. FAQ

Dosage Range

• CVI: HCSE standardised to 50-100 mg escin twice daily. The dose may be reduced to a maintenance dose of 50 mg escin once daily after 8 weeks.

• Australian manufacturers recommend 2-5 mL/day of 1:2 liquid extract.

• 1-2 g dried seed daily.

Adverse Reactions

According to clinical trials A. hippocastanum and horse chestnut standardised extract appear to be well tolerated with only mild, infrequent reports of adverse reactions including gastric irritation, skin irritation, dizziness, nausea, headache and pruritus. Post marketing surveillance reports adverse effects of 0.7% (Micromedex 2003, NMCD 2006, PDRHealth 2006).

Horse chestnut contains a toxic glycoside esculin (aesculin), a hydroxycoumarin that may increase bleeding time because of its antithrombin activity and may be lethal when the raw seeds, bark, flower or leaves are used orally. Poisoning has been reported from children drinking tea made with twigs and leaves.

Symptoms of overdose include diarrhea, vomiting, reddening of the face, severe thirst, muscle twitching, weakness, loss of coordination, visual disturbances, enlarged pupils, depression, paralysis, stupor and loss of consciousness.

Horse chestnut can also cause hypersensitivity reactions, which occur more commonly in people who are allergic to latex.

Isolated cases of kidney and liver toxicity have occurred after intravenous and intramuscular administration (Micromedex 2003, NMCD 2006).

Significant Interactions

ANTIPLATELET/ ANTICOAGULANT MEDICATIONS

Properly prepared HCSE should not contain esculin and should not carry the risk of antithrombin activity — observe. Clinical significance unclear.

HYPOGLYCAEMIC AGENTS

Due to possible hypoglycaemic activity, blood glucose levels should be monitored when horse chestnut or HCSE (horse chestnut standardised extract) and hypoglycaemic agents are used concurrently — observe. Clinical significance unclear.

Contraindications and Precautions

As saponins may cause irritation to the gastric mucosa and skin, A. hippocastanum should be taken with food, should not be applied topically to broken or ulcerated skin and should be avoided by people with infectious or inflammatory conditions of the gastrointestinal tract, including coeliac disease and malabsorption disorders.

Horse chestnut flower, raw seed, branch bark, or leaf may be toxic and are not recommended.

Avoid use in the presence of hepatic or renal impairment (Micromedex 2003, NMCD 2006, PDRHealth 2006).

Pregnancy Use

Safety in pregnancy and lactation has not been well established.

Practice Points / Patient Counselling

• Horse chestnut extract has been extensively researched for its beneficial effects and is commonly used by general practitioners in Germany for the treatment of CVI. There is strong evidence to support its use for this indication.

• In practice, a dry extract is used (HCSE standardised to contain 16-21% triterpene glycosides (anhydrous escin)).

• HSCE (horse chestnut standardised extract) is also used for venous leg ulceration because it increases venous tone while reducing venous fragility and capillary permeability, and possesses anti-oedema-tous and anti-inflammatory properties.

• HSCE is also used in the treatment of haemorrhoids. Although it has not been investigated for this indication, escin has been shown to significantly improve signs and symptoms under double-blind study conditions.

• HSCE is well tolerated with only mild, infrequent reports of adverse reactions including gastric irritation, skin irritation, dizziness, nausea, headache and pruritis.

• Horse chestnut can cause hypersensitivity reactions, which occur more commonly in people who are allergic to latex.

Answers to Patients’ Frequently Asked Questions

What will this herb do for me?

Horse chestnut standardised extract (HSCE) will relieve signs and symptoms of chronic venous insufficiency such as pain, pruritis and oedema. It may also be of benefit in alleviating signs and symptoms in peoplewith haemorrhoids and has been used in venous leg ulceration.

When will it start to work?

Beneficial effects in chronic venous insufficiency have been reported within 3-6 weeks; however, 12 weeks may be required in some cases. Escin provided symptom relief in haemorrhoids after 6 days of treatment.

Are there any safety issues?

HSCE is well tolerated with only mild, infrequent reports of adverse reactions including gastric irritation, skin irritation, dizziness, nausea, headache and pruritis. It can cause hypersensitivity reactions, which occur more commonly in people who are allergic to latex.