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Herb Groups
Glycoside-containing Herbs
Botanicals

Definition

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 Pharmacopeia. 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 herb group.

• herbal synergy: Hypotensive and Bradycardic herb group.

» 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 homostasis 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 herb group.

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

herbal synergy: Hypotensive and Bradycardic herb group.

• 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


Footnotes

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.