Poison Garden Plants

Oleander nerium (Austin Pretty Limits)

From University of Utah Health website

Oleander toxicity

Oleander Toxicity

There are numerous natural sources of cardioactive steroids, or cardiac glycosides, in addition to the well-known foxglove (Digitalis purpurea) and the pharmaceutical derivative digoxin. Other examples include red squill, lily of the valley, oleander (Nerium oleander), yellow oleander (Cascabela thevetia), dogbane, pong pong tree, milkweed, and sea mango. Ingestion of yellow oleander seeds is a common method of suicide in southeast Asia.1

Oleander (Figure 1) grows across the southern United States (Figure 2). The toxic cardenolide oleandrin is found in all parts of the plants with the greatest concentrations in the leaves. Toxicity has occurred with ingestion of multiple leaves or decoction of oleander. Toxicity is unlikely from small pediatric exposures.

Toxicity is similar to digoxin: nausea, vomiting, and cardiac abnormalities including bradycardia, various AV blocks, and ventricular dysrhythmias .2 Oleandrin is similar to digoxin and inhibits Na+/K+ ATPase leading to increased intracellular Na+ concentrations. This leads to diminished function of the Na+/Ca2+ antiporter causing increased intracellular Ca2+.

Digoxin immunoassays often cross-react with other structurally similar cardiac glycosides. However, the resulting concentrations should only be interpreted as “positive” and cannot be used to specifically guide treatment or quantify the amount of toxin present.