Cardiotoxic Plants Flashcards
What is the toxic principle of foxglove? What is its mechanism of action?
Digitalis (cardiac glycoside)
Inhibits Na/K ATPase-> increases vagal tone
How can you identify foxglove?
Black-brown speckling inside flowers (flowers are bright red or purple)
What are the clinical signs of foxglove toxicity?
GI upset, anorexia, blurred vision, disorientation
Increasing dose- bradycardia, arrhythmia, low blood pressure
High doses- CNS signs- depression, confusion, yellow-green tinge to vision
How do you treat foxglove toxicity?
Phenytoin
Lidocaine for arrhythmia
Digoxin antibody available, but limited
What is the toxic principle of lily of the valley?
Convallerin
Similar to digitalis
What are the clinical signs of oleander toxicity?
GI- oral irritation, abdominal pain
CV- tachycardia followed by bradycardia, arrhythmia, low blood pressure, pale MM, cold extremities
What is the toxic principle of milkweed?
Cardenolides (cardiac glycosides)
Also have galitoxin (neurotoxin)
What are the clinical signs of milkweed toxicity in livestock?
Whorled milkweed- depression, weakness, ataxia, tetanic convulsions, hyperthermia, coma
Broad leaf- bloat, slow, strong heartbeat -> rapid, weak heartbeat, cold extremities, prostration
What are the clinical signs of milkweed toxicity in dogs and cats?
Drooling, nausea, vomiting; arrhythmias, weakness, collapse; dilated pupils; tremors, seizure, death
What is the treatment for milkweed toxicity?
Rumenotomy and symptomatic treatment (chloral hydrate)
Digoxin-specific Fab fragments for dogs/cats (expensive)
What is the toxic principle of Kalanchoe? In what part of the plant is the highest concentration?
Cardenolides or bufadienolides
Flowers
What is a common electrolyte abnormality involving cardiac glycoside toxicity?
Hyperkalemia
What is the toxic principle of yew? How does its mechanism of action differ from plants containing cardiac glycosides like digitalis?
Taxine A and B
Inhibit Ca and Na channels
What are the clinical signs of yew toxicity?
Trembling, weakness, dyspnea, dilated pupils, ataxia, bradycardia, pulmonary edema, sudden death
What are the clinical signs of gossypol toxicity?
Weight loss, weakness, and dyspnea
