Glycoside-containing Herbs

Summary

Cardiac Glycoside-containing Herbs

introduction:
Cardiac glycoside-containing herbs are used therapeutically in the same way as are the pharmaceutical cardiac glycosides, such as digoxin, which are derived from them. Concentrations of cardiac glycosides in plants are low (<1.00% ). Three genera contain sufficient concentrations of glycosides for commercial extraction: Digitalis (Scrophulariaceae), Urginea (Liliaceae) and Strophanthus (Apocynaceae).

Neither Digitalis spp. or Strophanthus spp. are commonly used in herbal therapeutics and in many countries their use is legally restricted. Convallaria majalis (Lily of the Valley) and Urginea maritima are listed in the British Herbal Pharmacopoeia. Their cardenolides have low cumulative toxicity compared to Digitalis, and these plants are used by professional herbalists. For a comprehensive and authoritative discussion of use of cardiac glycoside-containing herbs in cardiology, see Rudolf Weiss's Herbal Medicine.
(Weiss RF, 1988.)

A few herbs in common use contain trace amounts of cardenolides and are not considered cardioactive. Some ornamental plants, such as the Oleanders, can cause digitaloid toxicity on accidental ingestion.

overview of interactions:
• herb affecting drug toxicity: Digoxin

• herbal support: Digoxin

• drug affecting herb toxicity: Loop Diuretics and Thiazide Diuretics

• herbal synergy: Hypertensive and Tachycardic Herbs

• herbal synergy: Hypotensive and Bradycardic Herbs



Herbs

herb affecting drug toxicity: Digoxin

• mechanism: Cardiac glycoside-containing will additively synergize with digoxin and related drugs.

herbal support: Digoxin

• mechanism: Cardiac glycoside-containing herbs may be used to reduce the dose of Digoxin, or to support weaning off Digoxin therapy.

drug affecting herb toxicity: Loop Diuretics and Thiazide Diuretics

• mechanism: Diuretic induced perturbations of potassium homeostasis may affect the toxicity of cardiac-glycoside-containing herbs.

• herbal concern: Herbal toxicity is a significant risk factor. Cardiac patients should never attempt self medication with cardiac glycoside-containing herbs due to the inherently narrow therapeutic index of these compounds.

herbal synergy: Hypertensive and Tachycardic Herbs

• mechanism: Glycoside-containing herbs may interact with herbs in this group through various synergistic or antagonistic mechanisms:

herbal synergy: Hypotensive and Bradycardic Herbs

• mechanism: Glycoside-containing herbs may interact with herbs in this group through various synergistic or antagonistic mechanisms:

Common herbs containing cardiac glycosides:
• Asclepias tuberosa (Pleurisy Root )*
• Convallaria majalis (Lily of the Valley)
• Scrophularia nodosa (Figwort) *
• Urginea maritima (Squill bulb)
note: * These herbs contain therapeutically insignificant quantities of glycosides.

Restricted or unusual herbs containing cardiac glycosides:
• Adonis vernalis (Pheasant’s Eye)
• Apocynum cannabinum (Canadian Hemp Root) toxic
Digitalis spp. (Foxglove) toxic
• Helleborus niger (Black Hellebore) toxic
• Helleborus viride (Christmas Rose) toxic
• Nerium oleander (Rose Laurel) toxic
• Strophanthus spp. (Ouabain, Kombe) toxic
• Thevetia neriifolia (Yellow Oleander) toxic




Please read the disclaimer concerning the intent and limitations of the information provided here.
Do not rely solely on the information in this article.

The information presented in Interactions is for informational and educational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, case reports, and/or traditional usage with sources as cited in each topic. The results reported may not necessarily occur in all individuals and different individuals with the same medical conditions with the same symptoms will often require differing treatments. For many of the conditions discussed, treatment with conventional medical therapies, including prescription drugs or over-the-counter medications, is also available. Consult your physician, an appropriately trained healthcare practitioner, and/or pharmacist for any health concern or medical problem before using any herbal products or nutritional supplements or before making any changes in prescribed medications and/or before attempting to independently treat a medical condition using supplements, herbs, remedies, or other forms of self-care.



References

Brinker F. Herb Contraindications and Drug Interactions. Second edition. Sandy, OR: Eclectic Institute Inc, 1998.

McGuffin M, et al. (eds.) AHPA Botanical Safety Handbook. CRC Press, 1997.

Newall C, Anderson L, Phillipson JD. Herbal Medicines: A Guide for Health-care Professionals. London: The Pharmaceutical Press, 1996.

Weiss RF. Herbal Medicine. Beaconsfield, England: Beaconsfield Publishers, 1988.