All parts of the
C. thevetia plant are toxic to most vertebrates as they contain
cardiac glycosides. Many cases of intentional and accidental poisoning of humans are known. Case reports have identified Tecojote root supplements as a source of accidental ingestion of yellow oleander. The main toxins are the
cardenolides
thevetin A and
thevetin B; others include
peruvoside,
neriifolin,
thevetoxin and
ruvoside. These cardenolides are not destroyed by drying or heating and are very similar to
digoxin from
Digitalis purpurea. They produce
gastric upset and
cardiotoxic effects, such as an
abnormally slow heart rate, EKG abnormalities (scooped ST segments), and
abnormally high levels of potassium in the blood. Antidotes include
atropine and
digoxin immune fabs (antibodies), and treatment may include oral administration of
activated charcoal. Ovine polyclonal anti-digitoxin Fab fragment antibody (DigiTAb; Therapeutic Antibodies Inc.) can be used to treat
T. peruviana poisoning, but in many countries the cost is prohibitively high. A few bird species are, however, known to feed on them without any ill effects. These include
sunbirds,
Asian koel,
red-whiskered bulbul,
white-browed bulbul,
red-vented bulbul,
brahminy myna,
common myna and
common grey hornbill. In South India and in Sri Lanka, swallowing the seeds of
Thevetia peruviana (Kaneru කණේරු (Sinhala), Manjal arali (Tamil)) is one of the preferred methods for suicides in villages where they are grown in abundance. Extracts from
C. thevetia are reported to possess antispermatogenic activity in rats. In 2023, the US
Centers for Disease Control and Prevention (CDC) and
Food and Drug Administration (FDA) reported on weight loss supplements which had substituted
Crataegus mexicana and
Aleurites moluccanus for
C. thevetia, following multiple hospitalizations. ==Uses==