Plants Flashcards
(156 cards)
toxic principle of foxglove
digitalis glycosides (present in flowers, seeds and leaves)
mechanism of action of foxglove
interferes with Na/K ATPase –> decreased intracellular K and increased intracellular Na –> increased Ca (interferes with normal electrical conductivity in myocardium)
clinical signs of foxglove toxicity
vomiting, colic, diarrhea, anorexia, CV (bradycardia, arrhythmias, heart failure), weakness, depression, dyspnea, tremors, convulsions, coma, death
diagnosis of foxglove
ECG, plant in stomach contents
PM of foxglove
gastroenteritis
treatment of foxglove
emesis, activated charcoal, saline cathartic, symptomatic and supportive, digibind (human product with cross reactivity to plant toxins)
toxic principle of japanese yew
alkaloid taxine; taxine B (wood, bark, leaves, seeds) – not present in fleshy fruit
toxic principle of japanese yew
alkaloid taxine; taxine B (wood, bark, leaves, seeds) – not present in fleshy fruit
japanese yew mechanism of action
disrupts Na and Ca currents in myocytes by binding receptors; depress conduction of myocardial depolarization
susceptibility of japanese yew
equine are more susceptible than ruminants (but both are susceptible)
clinical signs of japanese yew poisoning
rapid onset, sudden death, weakness, trembling, dyspnea, bradycardia, arrhythmias, convulsion, collapse
diagnosis of japanese yew poisoning
ECG abnormalities; alkaloid screen to ID toxin in stomach;
PM of japanese yew poisoning
gastroenteritis, secondary pulmonary congestion and edema
treatment of japanese yew poisoning
GI decontamination, activated charcoal, fluids, seizure control, treat arrhythmias
toxic principle of rhododendron
glycoside grayanotoxin (all plant parts, especially leaves)
mechanism of action of rhododendron toxicity
toxin binds and modified voltage gated Na channels on muscle membranes and nervous system –> leaves them in open position –> Na influx –> prolonged myocardial depolarization (paralysis); also increases intracellular Ca to have digitalis like effects on heart
clinical signs of rhododendron toxicity
salivation, projectile vomiting, diarrhea, anorexia, severe colic, depression, ataxia, paralysis, brady cardia, hypotension, arrhythmias
diagnosis of rhododendron toxicity
clinical signs and ID plant;
PM of rhododendron toxicity
degeneration of liver and kidneys (mild); GI irritation
treatment of rhododendron toxicity
aggressive GI decontamination, activated charcoal, symptomatic and supportive
toxic principle of jimson weed
tropane alkaloids (hyoscyamine, scopolamine, hyoscine) – all plant parts, especially seeds
mechanism of low dose jimson weed
competitive inhibitor of acetylcholine
mechanism of high dose jimson weed
direct CNS stimulation (crosses BBB rapidly)
clinical signs of jimson weed toxicity
atropine-like syndrome – mydriasis, anorexia, thirst, tachycardia, tachypnea, hypothermia, tremors, excitability, convulsions, death from resp paralysis