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Beware Oleandrin, It is a Deadly Cardiac Poison, Not a COVID-19 Cure

At The Conversation, Cassandra Quave (Assistant Professor of Dermatology and Human Health; Herbarium Curator, Emory University) has written a helpful article expressing her concern that the dietary supplements industry may try to take advantage of the public’s fear of COVID-19 by developing supplements containing oleandrin.

Interestingly, oleandrin is a cardiac glycoside like digitalis. I’ve written a lot about my love for the foxglove plant from which digitalis is obtained. Like digitalis, oleandrin has the potential for lethal cardiac rhythm abnormalities and comes from a beautiful plant.

Supplements and vitamins of various sorts have been widely and wildly recommended during COVID-19 with little good data to support any particular one.

The Cleveland Clinic Journal of Medicine published a nice review on the topic published in June which concludes:

Ascorbic acid, zinc, vitamin D, and N-acetylcysteine have biologic plausibility for the prevention and treatment of COVID-19 and are candidates for clinical trials evaluating patients with these indications. Although there is likely little risk for patients taking labeled over-the-counter doses of these supplements, clinical evidence does not currently support routine use of any of these agents for the prevention or treatment of COVID-19. Unless a patient has a confirmed or suspected micronutrient deficiency, additional research is needed before providing doses of these agents higher than the recommended daily intake established by the US Department of Agriculture.

I’ve been watching this area closely and feel it remains a good summary as of today, August 18, 2020. I have to admit that I had been diagnosed with low Vitamin D levels a year ago but had not been consistently taking my Vitamin D pills. Once COVID-19 began and an apparent association between low Vitamin D levels and severity of disease emerged I began taking my pills as prescribed.

Please note that these four supplements present little risk but many other supplements interact with prescription medications which can cause life-threatening adverse effects. In addition, unlike prescription medications, the supplement industry is not regulated by the FDA and you have no guarantees of safety, efficacy or event the content of OTC supplements.

The Conversation article is below the dots.

With COVID-19 cases and deaths rising in the U.S. and globally, identifying new therapies to prevent and combat the virus is a top priority. Natural products from plants are an attractive option in the search for a cure. Approximately 374,000 plant species are on Earth; humans have used more than 28,000 of them as a form of medicine. 

But not all that is natural is necessarily safe. Scientists have not yet explored most of these species for their chemical makeup or therapeutic potential. 

As a medical ethnobotanist, I study the traditional uses of medicinal plants to discover promising leads for new drugs to fight infectious diseases. It’s vital to consider both the potential benefits and risks of plant extracts in such research. I am concerned by recent reports that a chemical found in the oleander plant is being touted as a potential treatment for COVID-19. 

About the Oleander plant

Nerium oleander is a highly toxic plant from the Apocynaceae family. Though renowned for its beauty and use in landscaping, this Mediterranean shrub is responsible for cases of accidental poisoning across the globe. All parts of the plant are poisonous. If eaten, it causes cardiac arrhythmias, or irregular heart rates, and can be lethal to both humans and animals. 

The chemical structure for oleandrin, the toxic compound in the beautiful plant oleander. Casssandra Quave, CC BY-SA

Oleandrin is the chemical that causes the plant’s lethal toxicity. It is known by scientists as a cardiac glycoside, a class of organic compounds with a common feature: They exhibit powerful effects on heart tissue, often with deadly consequences.

A pre-print article – that is, an article not peer-reviewed by other scientists – is now online. It reports how, in a test tube, oleandrin reduces production of the virus responsible for COVID-19. But this does not take into account the well-known cardiac toxicity of the chemical when consumed by an animal or human.

Particularly worrisome is the idea that consumers may misinterpret any publicity surrounding oleander and try to self-medicate with this highly poisonous plant. I’m also concerned the dietary supplements industry may try to take advantage of the public’s fear of COVID-19 by developing supplements containing oleandrin. 

There are many other examples of natural plant extracts that are harmful. But oleander is particularly dangerous, because ingesting any part of the plant can lead to serious illness and possibly death. What’s more, there is no published scientific evidence on the safety of consuming oleandrin or its plant source, Nerium oleander. It is critical that the Food and Drug Administration and its commissioner, Dr. Stephen Hahn, make certain the public is protected from this poison.

I will definitely be steering clear of oleander supplements during COVID-19 but hope to add Nerium oleander to my garden of cardiologogic plants in the near future.

Digitallicly Yours,


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