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 (Pheasants 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.
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.
Do not rely solely on the information in this article.
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.