Karavira: A Deadly Poison — Oleander Toxicity, Classical Context & Safety

TL;DR

Karavira (Nerium indicum, Indian oleander) is a deadly poison: all parts contain oleandrin and other cardiac glycosides that can cause fatal cardiac arrhythmias and arrest. Yellow oleander, a related species, is a documented means of intentional self-poisoning in South Asia. Classical texts treat it as a poison first, and this article gives no dose or preparation instructions for any condition.

What it is

Karavira is the Ayurvedic name for the Indian oleander: Nerium indicum Mill. (syn. Nerium odorum Soland; widely treated as the same plant as Nerium oleander L.), a large evergreen woody shrub of the family Apocynaceae with milky sap, grown across the upper Gangetic plains, the Himalayan foothills, and temple and household gardens (JETIR botanical-identity review; Chaudhary 2015). Ayurvedic nighantus distinguish varieties by flower colour: the white and red varieties correspond to Nerium indicum, while the yellow-flowered "pita karavira" is a different species: Thevetia peruviana, yellow oleander (JETIR review).

Every part of the plant is poisonous: leaves, flowers, seeds, bark, roots, and sap. The toxicity comes from cardiac glycosides (cardenolides), chiefly oleandrin, with nerin, digitoxigenin, and olinerin also present; oleandrin is the principal toxin (Toxins review; Radenkova-Saeva & Atanasov 2014). These compounds inhibit the Na⁺/K⁺-ATPase pump in cell membranes, raising intracellular sodium and then calcium in heart muscle: producing both stronger contractions and lethal rhythm disturbances (Langford & Boor, Toxicology 1996). There is no part of this plant that is safe to eat or brew: toxicity has followed teas brewed from its parts (Acta Medica Bulgarica 2014), and even the smoke produced from burning oleander contains cardiac glycosides, because heat does not inactivate them (Heart Views case report).

In South Asia, oleander is a documented means of intentional self-poisoning. In northern Sri Lanka, self-poisoning with yellow oleander (Thevetia peruviana) seeds reached epidemic proportions (Eddleston et al. 1999, cited in), and a 2020 hospital series from a tertiary care center in South India described 30 admitted oleander-poisoning patients: again yellow oleander, a different species from Karavira: 80% presented with vomiting, half had ECG abnormalities (most commonly AV block), and two died in hospital (6.7%) (Karthik et al., Journal of Family Medicine and Primary Care 2020). The species differ, but the cardiac-glycoside poisoning picture is the same one Nerium produces. For Nerium specifically, a forensic case report (published online 2023) documents a child who died about 36 hours after accidentally eating oleander leaves mistaken for guava leaves: with hyperkalemia, acute kidney injury, and myocardial dysfunction (Ayyappan et al., Forensic Science, Medicine and Pathology).

Traditional use

Classical Ayurveda treated karavira as a poison first: the texts record hazardous specialist uses alongside explicit warnings that all parts of the plant, especially the roots, are lethally toxic when taken internally (Chaudhary 2015, Journal of Pharmacognosy and Phytochemistry). Separately, a 2014 toxicology review notes that oleander preparations were formerly used as remedies for indigestion, fever, malaria, leprosy, and venereal diseases, and as abortifacients, as well as rodenticides and insecticides (Radenkova-Saeva & Atanasov, Acta Medica Bulgarica 2014).

These are historical records of a dangerous practice, not endorsements and not instructions. Nothing in the classical literature makes any karavira preparation safe for home use, and no clinical trial has ever tested a karavira preparation for any condition.

What modern research says

How the poison works

Oleandrin is rapidly absorbed through the gut (oral bioavailability roughly 30–40%), distributes widely with affinity for the heart, and has an elimination half-life of about 5–22 hours: long enough to prolong the danger (Toxins review). Poisoning typically declares itself within hours of ingestion with gastrointestinal effects (nausea, vomiting, salivation, colic, diarrhea), followed by the cardiac effects that kill: bradycardia or tachycardia, heart block, ventricular arrhythmias, and cardiac arrest. ECG changes include prolonged PR interval and T-wave flattening or inversion. Neurological effects, confusion, drowsiness, ataxia, muscular tremor, can follow (Toxins review; Radenkova-Saeva & Atanasov 2014; Heart Views case report). A forensic case report (published online 2023) documents a child who died about 36 hours after accidentally eating oleander leaves mistaken for guava leaves (Ayyappan et al., Forensic Science, Medicine and Pathology).

Management of poisoning

There is no home remedy and no home treatment. Emergency hospital care is supportive and time-critical: focused on limiting further absorption and stabilizing the heart rhythm. In severe cases, some hospitals use digoxin-specific antibody fragments, which cross-react with oleander cardiac glycosides (Heart Views case report; Toxins review).

What the evidence does not support

No human clinical trial establishing karavira as a treatment for any condition was identified in the sources surveyed. The classical uses rest on Ayurvedic texts, not on clinical evidence: and the poisoning literature shows that fatal poisoning has followed relatively small ingestions: one calculated lethal dose was approximately 4 g of oleander leaf (Heart Views case report).

Dosage

No dosage is given in this article: deliberately. There is no safe dose of karavira for any person to self-administer, and publishing one would be irresponsible. Do not seek out dosing information for this plant from any source, including traditional or "natural medicine" websites.

Safety & contraindications

FAQs

Is karavira used safely in Ayurvedic medicine?

Classical texts treat karavira as a poison first, recording only hazardous specialist uses alongside explicit warnings that all parts, especially the roots, are lethally toxic when taken internally (Chaudhary 2015). There is no traditional or modern basis for ingesting it.

What are the symptoms of oleander poisoning?

Nausea, vomiting, abdominal pain, and diarrhea; slow, fast, or irregular heartbeat and palpitations; confusion, drowsiness, dizziness, and visual disturbances; in severe cases, heart block, ventricular arrhythmias, and cardiac arrest. Symptoms typically begin within hours of ingestion (Toxins review).

What should I do if someone ingests oleander?

Call emergency services or poison control immediately: do not wait for symptoms to appear. Do not try to induce vomiting or administer home remedies. Treatment must happen in a hospital, where care is supportive and time-critical (Heart Views case report).

What is the difference between karavira and yellow oleander?

Karavira (Nerium indicum / N. oleander, the white/red kaner) and yellow oleander (Thevetia peruviana, "pita karavira") are different species in the same family. Both contain lethal cardiac glycosides and both have caused fatal poisonings; neither is safe (JETIR review; Toxins review).

Can I keep oleander as a garden plant?

It is a common ornamental worldwide, but every part is poisonous and children have died after mistaking the leaves for edible ones (Ayyappan et al., Forensic Science, Medicine and Pathology). If you grow it, keep it away from children and pets, avoid contact with the sap, never burn the clippings: the smoke contains cardiac glycosides, as heat does not inactivate them (Heart Views case report): and never ingest any part.

Sources

Disclaimer

This article is for educational purposes only and is not medical advice. Karavira (Nerium indicum / Nerium oleander) is a deadly poison. Never ingest, brew, or chew any part of this plant. If exposure is suspected, call emergency services or your local poison control center immediately. Do not attempt any traditional processing method at home under any circumstances.