14 Poisonous Plants, part 1

Question 1

The most straightforward approach for emergency physicians in classification of plants

Answer 1

to classify toxic plants by the mechanism of action of the toxin and then to further subclassify based on the specific toxin

Question 2

Most commonly reported effects of plant toxicity

Answer 2

dermatitis and GI irritation

Question 3

Disposition for plant poisoning

Answer 3

DISCHARGE asymptomatic patients and those with resolved minor toxicity after 4-6 hours of observation, with strict return precautions.

ADMIT those with more than minimal findings because toxicity may continue to evolve in those patients exposed to toxins with delayed onset (e.g., cyanogenic glycosides, mitotic inhibitors, or taxalbumins)

This approach is generally applied to all patients with plant exposure because the scientific literature lacks adequate data to provide less conservative recommendations

Question 4

Plant with nicotine-like toxins (A)

Answer 4

Poison hemlock
- cause of death of Socrates
Lupin

Question 5

Plants with sodium channel toxins (B)

Answer 5

Yew
Contains taxine alklaoids
Azalea
Rhododendron
Laurel
Contain grayanotoxins

Question 6

Correlates with the development of ventricular dysrhythmias

Answer 6

Higher aconite alkaloid concentrations
- found in monkshood and larkspur
- these alkaoids activate cardiac, and less so neuronal, sodium channels

Question 7

sometimes used in traditional Chinese medicine as an inotrope

Answer 7

Monkshood

Question 8

(C) Cardioactive steroids are found in

Answer 8

Foxglove (Digitalis spp)
Dogbane
Lily of the Valley
Milkweed

Question 9

Remarks on cardiac steroids

Answer 9

1. A.k.a. cardiac glycosides)
2. they inhibit Na/K ATPase pump
3. Acute toxicity closely resembles that from digoxin, and includes early GI effects followed by cardiac dyrhythmias

Question 10

Treatment of cardiac steroids toxicity

Answer 10

1. Oral activated charcoal
2. Digoxin immune Fab fragments if K >5 mEq/L or any cardiac dysrhythmia
   - unlike with digoxin, antidote dosing should be empiric (10 vials as an initial dose)

Question 11

Other things regarding treatment of cardiac steroids toxicity

Answer 11

1. Avoid transvenous pacing and calcium administration for the inccreased theoretical risks of inducing a dysrhythmia
2. Traditional treatments for hyperkalemia such as insulin, calcium, sodium bicarbonate, or hemodialysis are usually unnecessary if digoxin immune Fab is administered

Question 12

(D) Plants with toxalbumins

Answer 12

Castor bean (contains ricin)
Rosary pea (contains abrin)
Jatropha seed “Tuba-tuba” (contains curcin)
Americal mistletoe
European mistletoe

Question 13

Remarks on ricin

Answer 13

1. A potential biologic weapon and has been implicated in a number of attempted assassinations
2. Exerts its toxicity by entering cells and inhibiting protein synthesis
3. Enteral absorption of ricin is poor, which tends to limit toxicity to diarrhea and abdominal pain

Question 14

Remarks on Jatropha seed

Answer 14

a.k.a “Tuba-tuba”, “purging nut”, “psychic nut”

Contains ricin or curcin, tanic acid and gallic acid.

Mature seeds contain higher concentrations of the toxic substances, and are therefore more toxic than young seeds.

The main effects of jatropha seeds are gastric irritation and hepatic damage.

Hypocalcemia and hypoprothrombinemia are also seen.

Question 15

Treatment of toxalbumin ingestion

Answer 15

Activated charcoal followed by a lengthy observation period

All routes of exposure can be fatal, but hydration and aggressive supportive care significantly reduce mortality. 💯

Question 16

(E) Plants that impair GABA receptor [or potassium channel function]

Answer 16

Water hemlock
All parts of the plant are poisonous, with the highest concnetration of cicutoxin in the tuber

Question 17

(F) Plants that cause demyelination

Answer 17

Buckthorn or coyotillo
Contain demyelinating anthracenones that lead to progressive muscle weakness that resembles GBS