Merck Manual

Please confirm that you are a health care professional

Loading

Plant Poisoning

By

Gerald F. O’Malley

, DO, Grand Strand Regional Medical Center;


Rika O’Malley

, MD, Albert Einstein Medical Center

Last full review/revision Apr 2020| Content last modified Apr 2020
Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Topic Resources

A few commonly grown plants are highly poisonous, and many plants are moderately poisonous (see table Moderately Poisonous Plants). Few plant poisonings have specific antidotes. Most plant ingestions, including the plants listed in the table Moderately Poisonous Plants, result in minimal symptoms unless the leaves and other components are concentrated into a paste or brewed into a tea.

Highly toxic and potentially fatal plants include the following:

  • Castor beans and jequirity beans

  • Oleander and foxglove

  • Hemlock

Castor beans and jequirity beans

Castor beans contain ricin, an extremely concentrated cellular poison. Jequirity beans contain abrin, a related and even more potent toxin. In both, the beans have a relatively impervious shell; thus, the bean must be chewed to release the toxin. However, the seed coating of the jequirity bean is often not intact, and simple bacterial digestion can release the abrin toxin.

Symptoms of either poisoning may include delayed gastroenteritis, sometimes severe and hemorrhagic, followed by delirium, seizures, coma, and death. Whole-bowel irrigation should be considered because it aims to remove all beans ingested.

Oleander and foxglove

These plants and lily of the valley (which is similar but less toxic) contain digitalis glycosides. Toxicity includes gastroenteritis, confusion, hyperkalemia, and arrhythmias. The serum digoxin level can confirm ingestion but is not useful as quantitative information.

Potassium levels are closely monitored. Hyperkalemia may respond only to hemodialysis. Calcium is not recommended for arrhythmias. Digoxin-specific fractionated antibody (Fab) fragments have been used to treat ventricular arrhythmias.

Hemlock

Hemlock poisoning (poison hemlock and water hemlock) can cause symptoms within 15 minutes.

Poison hemlock has nicotinic effects, beginning with dry mouth and progressing to tachycardia, tremors, diaphoresis, mydriasis, seizures, and muscle paresis. Rhabdomyolysis and bradycardia may occur.

Water hemlock seems to enhance gamma-aminobutyric acid (GABA) activity. Symptoms may include gastroenteritis, delirium, refractory seizures, and coma.

Table
icon

Moderately Poisonous Plants

Plant

Symptoms

Treatment

Aconitine (eg, derived from monkshood)

Bradycardia, arrhythmias, paresthesia, weakness

Supportive care

Sodium bicarbonate

Aloe spp

Gastroenteritis, nephritis, skin irritation

Supportive care and skin irrigation with soap and water

Aristolochia spp (birthworts, pipevines)

Supportive care

Azalea

Cholinergic symptoms

Supportive care and atropine

Caladium spp (elephant ear, angel's wings)

Oral mucosal damage due to calcium oxalate crystals in leaves

Supportive care and demulsification (eg, with milk or ice cream)

Capsicum spp (peppers)

Mucous membrane irritation and swelling

Supportive care, irrigation

Colchicine (autumn crocus, meadow saffron, glory lily)

Delayed gastroenteritis, multiple organ failure

Bone marrow suppression

Supportive care and possibly, as a last resort, experimental colchicine-specific Fab fragments*

Cyanogenic glycosides (eg, in Prunus spp [eg, peach, apricot, and wild cherry pits], Malus spp [eg, apple seeds], and other seeds)

Symptoms of cyanide poisoning

Hydroxocobalamin

Cyanide antidote kit (includes amyl nitrate, sodium nitrite, and sodium thiosulfate)

Deadly nightshade

Anticholinergic symptoms, hyperthermia, seizures, hallucinations

Supportive care

For severe hyperthermia or seizures, possibly physostigmine

Dieffenbachia (dumbcane)

Oral mucosal damage due to calcium oxalate crystals in leaves

Supportive care and demulsification (eg, with milk or ice cream)

Fava beans

In patients with G6PD deficiency, gastroenteritis, fever, headache, hemolytic anemia

Supportive care

For severe anemia and poisoning, consideration of exchange transfusion

Green potato and potato sprout

Gastroenteritis, hallucinations, delirium

Supportive care

Holly berries

Supportive care

Jimsonweed

Anticholinergic symptoms, hyperthermia, seizures, hallucinations

Supportive care

For severe hyperthermia or seizures, possibly physostigmine

Licorice (not the artificially flavored licorice candy)

Hypokalemia, hypertension, and retention of water and sodium (pseudohyperaldosteronism)

Supportive

Lily of the valley

Mistletoe

Supportive care

Nettle

Local stinging and burning

Supportive care

Nightshade, common or woody

Gastroenteritis, hallucinations, delirium

Supportive care

Pennyroyal

Hepatotoxicity

N-Acetylcysteine

Philodendron spp

Oral mucosal damage due to calcium oxalate crystals in leaves

Supportive care and demulsification (eg, with milk or ice cream)

Poinsettia

Minor mucous membrane irritation

Unnecessary

Poison ivy

Dermatitis

Pokeweed

Mucous membrane irritation, gastroenteritis

Supportive care

Pothos

Oral mucosal damage due to calcium oxalate crystals in leaves

Supportive care and demulsification (eg, with milk or ice cream)

Yew

Rarely, seizures, arrhythmias, coma

Supportive care

* Available only in France.

Fab = fractionated antibodies; sp/spp = species.

Drugs Mentioned In This Article

Drug Name Select Trade
NITHIODOTE
No US brand name
CYANOKIT
ACETADOTE
COLCRYS
ATROPEN
LANOXIN
Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read

Also of Interest

Videos

View All
How to Remove a Cast
Video
How to Remove a Cast
3D Models
View All
Thorax
3D Model
Thorax

SOCIAL MEDIA

TOP