(Apocynaceae), an evergreen ornamental plant native only in the Mediterranean, is cultivated worldwide, particularly in areas with warm temperate climates and subtropical areas. Elsewhere, where the shrub is not frost-tolerant (for example, in Central and Western Europe), it may be grown as a conservatory plant. Oleander leaves and seeds contain more than 30 different cardiac glycosides. It was formerly used as a cardiac tonic and diuretic, and extracts are still used in homeopathy.1
All parts of this plant, including the sap—fresh, dried or boiled—are toxic.2
In children, a single leaf may be lethal.3,4
It causes poisoning in animals much more than in humans.5,6
The present study reports a case of poisoning with oleander bloom in a subject who subsequently recovered following conservative treatment only, the first such outcome to be reported in the literature.
To date, only a few studies of oleander poisoning in humans have been published.7–12
However, due to discrepancies in digitoxin/digoxin immunoassay results,13
the toxicological data reported are quite inhomogeneous and it appears that only the identification of oleandrin by chromatographic procedures permits a conclusion for the degree of toxicity. For example, in two cases of oleander poisoning in adults, comparable digoxin concentrations of 1.2 ng/ml7
and 1.5 ng/ml,8
respectively, in the blood samples were obtained; in these cases the immunoassays used yielded completely different results—mild cardiac symptoms7
In contrast, well defined toxicological data were published by Tracqui et al10
who reported 1.1 ng/ml oleandrin (venous blood) in a non-fatal case that resulted in mild cardiac symptomatology, and by Arao et al11
who reported 9.8 ng/ml oleandrin (heart blood) in a case of fatal poisoning. The presented non-fatal case confirms the report of Tracqui et al10
both in the mild cardiac symptoms and the concentration of oleandrin measured in femoral blood. Pietsch et al12
proposed classifying an oleandrin value between 1.0–2.0 ng/ml as a toxic blood plasma/serum concentration. In contrast, the study of Wang et al14
reported an oleandrin plasma concentration of 7 ng/ml in a volunteer 3 h after an intramuscular dose of 15 mg oleander extract for cancer treatment. This value is remarkably high compared to our case as well as other case reports,10,11
and can be explained only by an acquired tolerance of the volunteer.
The symptoms and treatment in oleandrin poisoning do not depend on the oleandrin plasma concentration and the patient’s clinical state. In the case reported by Wasfi et al
the symptoms were complicated by complete heart block, cardiac arrest, ventricular fibrillation and multiple organ failure, with a ~10 ng/ml oleandrin serum concentration. The patient was connected to a mechanical ventilator and received fentanyl, propofol, morphine, midazolam and digoxin binding antibody, but still died. In the case reported by Pietsch et al
the patient had improved intermittent AV block III° and was treated conservatively (charcoal combined with sodium sulfate and a temporary external cardiac pacemaker) with a 1.6 ng/ml oleandrin serum concentration. In the present study, in spite of a high serum oleandrin concentration (~14.7 ng/ml), the patient was treated conservatively. This is the first case to be reported in which the patient survived with such a high serum oleandrin concentration.
This report of non-fatal oleander poisoning underlines the importance of toxicological services in such a clinical emergency. All compounds of N oleander are toxic. N oleander produces typical clinical signs of cardiac glycoside poisoning, and the most common and potentially fatal signs are cardiac. The approach to treatment depends on the patient’s neurological, cardiac and circulatory stability.
The limitation of the present study is that we were not able to analyse the blood samples and oleander leaves by liquid chromatography/mass spectrometry (LC/MS/MS) for oleandrin and related compounds, the main cardiac glycosides of N oleander.
- This is the first case report of oleander poisoning in which the patient recovered with conservative treatment only.
- Poisoning due to oleander is rarely seen.
- Most cases of oleander poisoning result in death.