Reacts with acetylcholinesterase

Loss of alkyl group results in irreversible binding

Tx: Decontaminate

Atropinization

Artificial respiration, monitoring heart rate and secretion

Pralidoxime in first 24 hours to reactivate debilitated enzyme

Blocks binding of the inhibitory transmitter GABA to receptors 

Decreases Na and K conductance in axonal membranes

Tx: Decontaminate (wash skin)

Methocarbamol: muscle relaxant

Diazepam  or phenobarbital for seizures

Activated charcoal to reduce enterohepatic cycling

Interferes with sotrage of neurotransmitters in the brain, including norepinephrine, serotonin, and GABA

Tx with methocarbamol/diazepam

Tx: Decontaminate

Vitamin K1 - may need to maintain therapy for 30 days

Tx: Asymptomatic - induce vomiting

Due not indcue vomiting if symptoms appear. Use sedation and activated charcoal

Diazepem or barbiturates to raise threshhold of spinal reflexes

methocarbamol

Respiration should be monitored

Tx: Increase excretion of toxin, correct dehydration, increase urine production with IV fluid

Prevent metabolism of toxin by administering 4-Methylpyrazole or ethanol (competes for alcohol dehydrogenase enzyme active site)

sodium bicarb

Excessive exposure = conversion of N-acetyl-p-benzoquinoneimine increases

Stores of glutathione become depleted → hepatic cellular damage can take place

Tx: Decontaminate

Supply sulfur to replenish glutathione stores

Cimetidine inhibits cytochrome P-450 and may reduce toxic metabolite formation

Inhibits enzyme phosphodiesterase, resulting in increase intracellular cAMP

Competitive antagonist of purinergic transmitter adenosine

Tx: Iv fluids for rehydration and diuresis (increase elimination)

Diazepam/barbiturates/anesthesia for seizures

β-antagonists propranolol or metaprolol for cardiac signs

Lidocaine can be used to control ventricular arrhthymias

Central neuronal inhibition of GABAergic receptors - tremors followed by seizures - respiratory failure

muscle degeneration may occur if animal survives

Tx by decontaminating and pentobarbital for seizures

Toxin oxidizes hemoglobin → Heinz body formation, methemoglobinemia (hydrogen peroxide in excess of cells own detox mechanisms), hemolytic anemia

Intravascular hemolysis: erythrocyte damage and lysis

Extravascualr hemolysis: hemoglobin oxidation

Tx: Activated charcoal, fluids to maintain kidney function, blood transfusions

Ascorbic acid

Tx: Cholestyramine to interrupt entero-hepatic cycle

Antibodies that bind glycoside and are removed by the kidney

Antiarrhytmic drugs

HCN has high affinity for Fe3+ in cytochrome oxidase → prevents cellular respiration → death

Neurotoxicity/goitrogenic if exposure is chronic

Tx: Sodium nitrate converts some hemoglobin to methemoglobin, which competes with cytochrome oxidase for CN forming cyanmethemaglobin → reactivates cytochrome oxidase

Sodium thiosulfate and CN can be converted to sodium thiocyanate in presence of rhodanese enzyme

Disulfides are involved in the foramtion of free radicals which can damage the membranes of erythrocytes causing hemolysis

Free radicals + hemoglobin = Heinze body formation

Anemia with high doses

Tx: Cardiovascular support, Transfusions 

Do not stress the animal

Severe damage to the renal tubular epithelium and sloughing of tubular cells occurs

Polyuric renal failure followed by dehydration and anuric stage

Tx: Pre-anuric stage: fludid therapy

Post-anuric stage: Peritoneal dialysis or hemodialysis may proove life saving

Inhibit nuclear RNA polymerase → decrease messenger RNA → decreased protein synthesis

Hepatocytes, renal tubular cells, GI epi are most vulnerable due to high metabolic rate

→

Horses and related species effected

Wilted and dried leaves are more toxic than fresh. Bark is toxic

All parts of the plant contain toxic glycosides

Both fresh and dry material is toxic

Cyanogenic compounds

Most common: glycosides amydalin and prunasin

Cats affected

Consumption of any part produces toxicity

cyclopeptides -amatoxins, phallotoxins - liver failure

Some species contain the parasympathomimetic agent muscarine