Oleander (Nerium oleander) poisoning causes death by the same mechanism as digitalis glycosides. The primary target and lethal mechanism is:

• A Blockade of beta-adrenergic receptors reducing heart rate to zero
• B Direct neurotoxicity via acetylcholine release at the sinoatrial node
• C Hypokalaemia from potassium channel activation in cardiomyocytes
• D Inhibition of sodium-potassium ATPase (Na+/K+-ATPase) in cardiac cells, causing intracellular calcium overload and fatal arrhythmias ✓

Explanation

Oleandrin and neriine from Nerium oleander are cardiac glycosides that, like digoxin, inhibit the Na+/K+-ATPase pump on cardiac cell membranes. This increases intracellular sodium, which in turn elevates intracellular calcium via the sodium-calcium exchanger. Excess intracellular calcium causes afterdepolarisations, ventricular tachycardia/fibrillation, and AV block. The serum potassium rises (hyperkalaemia) due to pump inhibition. Anti-digoxin Fab fragments are used as an antidote.

Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.