Yarrow Drug Information – Precautions to be kept in mind while using Yarrow
24 September 2007Taxonomic Class
Asteraceae
Common Trade Names
Diacure, Lasadoron, Rheumatic Pain Remedy, Yarrow Flowers
Common Forms
Capsules: 320 mg, 340 mg
Liquid extract: 1 oz, 2 oz
Also available as cut herb, essential oil, powder, and tincture.
Source The drug is extracted from the dried leaves and flowering tops of Achillea millefolium, a plant that is native to Europe and Asia and naturalized in North America. The plant is a member of the daisy family.
Chemical Components
Yarrow contains tannins, amino acids, fatty acids, sesquiterpene lactones, and peroxides.
Actions
Yarrow is claimed to have anti-inflammatory and antispasmodic actions. It is also believed to have astringent, diaphoretic, GI stimulatory, and vasodilatory effects. Some sesquiterpenoid compounds isolated from the herb have been reported to display activity against mouse P-388 leukemia cells in vivo .
Other studies in mice have demonstrated an antispermatogenic effect from daily administration of a yarrow extract .
Reported Uses
Yarrow has been used as an emergency styptic applied externally to heal wounds and as an external wash for eczema. Taken internally, the herb is thought to reduce phlegm and other symptoms associated with respiratory tract infections; it has also been used in disorders of the digestive, female reproductive, and urinary systems.
Dosage
Dried herb: 2 to 4 g as a tea P.O. t.i.d.
Liquid extract (1:1 in 25% alcohol): 2 to 4 ml P.O. t.i.d.
Tincture (1:5 in 45% alcohol): 2 to 4 ml P.O. t.i.d.
Adverse Reactions
GU: uterine stimulant (with increased doses).
Skin: allergic contact dermatitis (in up to 50% of patients photosensitivity (conflicting reports).
Interactions
Anticoagulants: May increase anticoagulant effect. Use cautiously with yarrow.
Antihypertensives: May increase hypotensive effect. Monitor the patient.
CNS depressants: May increase sedative effect. Use cautiously with yarrow.
Disulfiram: May cause a disulfiram reaction if the herbal product contains alcohol. Avoid administration with yarrow.
Contraindications and Precautions
Yarrow is contraindicated in patients who are hypersensitive to yarrow or other members of the Asteraceae family. Avoid its use in pregnant or breast-feeding patients; effects are unknown. Use cautiously in men because of a potential inhibitory effect on spermatogenesis that has been documented in animal studies.
Special Considerations
- Monitor for adverse CNS effects.
- Monitor blood pressure of the patient who is also taking an antihypertensive.
- Caution the patient taking disulfiram to avoid using an herbal product that contains alcohol.
- Advise women to avoid using yarrow during pregnancy or when breast-feeding.
- Caution the patient to avoid hazardous activities until yarrow’s CNS effects are known.
- Advise the patient with skin allergies to avoid handling the plant.
- Instruct the patient to discontinue using yarrow if bleeding, rash, or unusual signs or symptoms occur.
Points of Interest
- Yarrow obtained its scientific name, Achillea, from the warrior Achilles of Homeric legend. At the battle of Troy, a Greek god appeared and showed Achilles how to stop bleeding by applying yarrow leaves.
Commentary
Although yarrow has many folk uses, there are no clinical studies for any disease state in humans. Therefore, it should be used cautiously in view of its apparent tendency to cause contact dermatitis.
Tagged under:achillea millefolium, Anticoagulants, Antihypertensives, antispasmodic, Herbal Medicines yarrow flowers
