Thevetia peruviana (pers). K Shum1.2

FamilyApocynaceae1.3 Common name(s)Be still TreeDigoxinLucky NutNerium oleanderYellow Oleander2.

SUMMARY2.1 Main risks and target organsThe main toxic effects of glycosides found in Thevetiaperuviana are related to its digitalis-like action on theheart and severe gastrointestinal irritation.

2.2 Summary of clinical effectsThe common presenting symptoms are: numbness, burning of themouth, nausea, vomiting, abdominal pain and diarrhoea. Otherfeatures seen are: drowsiness, coma, occasional convulsions,and cardiac arrhythmias. Death is due to ventricularfibrillation.

2.3 DiagnosisDiagnosis depends on the patient's history and the clinicalpresentation. Cardiac glycosides can be investigated in the blood bycompetitive immunoassay. The serum potassium concentrationshould be monitored. Electrocardiography, frequent serumelectrolytes (especially potassium concentration), and renalfunction tests are essential investigations. Remnants ofseeds, vomitus or gastric aspirate should be collected foridentification purposes.

2.4 First-aid measures and management principlesAdmit the patient to a hospital. Treatment should aim at a)gut contamination by emesis or lavage if the ingestion isrecent; b) correction of electrolyte imbalance; c) correctionof severe bradycardia with atropine or electrical pacing andcorrection of ventricular dysrrhythmias; and d)administration of digoxin Fab antibodies if available.

2.5 Poisonous partsAll parts of the plant, particularly the seeds are poisonousowing to the presence of cardiac glycosides or cardiac toxinswhich act directly on the heart. Ingestion of these plantparts could lead to death. The whole plant exudes in a milkyjuice which is very poisonous.

2.6 Main toxinsThevetin A, Thevetin B and Peruvoside.

3. CHARACTERISTICS3.1 Description of the plant

3.1.1 Special identification featuresIt is a small ornamental tree which grows to about 10 to15 feet high. The leaves are spirally arranged, linearand about 13 to 15 cm in length. Flowers are brightyellow and funnel-shaped with 5 petals spirally twisted. The fruits are somewhat globular, slightlyfleshy and have a diameter of 4 to 5 cm. The fruits,which are green in colour, become black on ripening.Each fruit contains a nut which is longitudinally andtransversely divided. All parts of the plant containthe milky juice.

3.1.2 HabitatGrown as an ornamental tree in gardens.

3.1.3 DistributionThis plant is native of Central & South America, but nowfrequently grown throughout the tropical and sub-tropical regions.

3.2 Poisonous parts of the plantAll parts of the plant are poisonous, especially the kernelsof the fruit. The absorption of the equivalent of two Thevetia peruvianaleaves may be sufficient to kill a 12.5 kg child (Ellenhornand Barceloux, 1988).