Miscellaneous toxins Flashcards
Sources of zinc
Pennies (after 1982)
Zippers, toys, board game pieces, supplements, diaper rash ointment
Zinc mechanism of toxicity
Absorption from GI tract → stomach acid releases free zinc/ salts from object → binds to albumin and metabolized in liver → secreted in bile/ feces → GI upset →hemolytic anemia
CS of zinc toxicity
V/D and anorexia → intravasc hemolysis (pale mm, tachycardia, Hbnemia, Hburia, depression)
Severe signs associated with zinc toxicity
Recumbency, seizures, oliguria, anuria and death
Minimum database for zinc toxicity
CBC (regenerative anemia and heinz bodies)
Chem (↑ BR, +/- ↑ liver enzymes and azotemia)
Urinalysis (proteinemia, Hburia, BRuria)
Confirmatory tests for zinc toxicity
Specific tubes (royal blue), clean stick
>5 ppm =toxicity
Tx for zinc toxicity
Remove object (emesis, endoscopy*, gastrotomy)
Supportive (hydration, blood transfusions, control vomit)
Differentials for acute hemolysis
Onion/ garlic, acetaminophen, rattlesnake bites
Ethylene Glycol
Dogs more exposed, cats more severe
Rapid oral absorption
MOA for EG
ADH broken down to glycoaldehyde (CNS signs) → glycolic acid (acidosis) → oxalic acid → Ca oxalate crystals move into tubules causing severe kidney damage
CS of EG
Neurologic: CNS depression and staggering/ drunken sailor
Cardiopulmonary: stupor phase + acidosis
Renal: ↑ depression, ataxia, anorexia, AKI
EG dx
Start tx B4 confirmed dx!!!
EG vet test strips, CBC/ Chem/ US, acid base urinalysis
Anion gap >25
EG tx
Induce emesis, IV fluids
4-methylpyrazole and ethanol
EG prognosis
Azotemia, oliguric/ anuric= grim prognosis
↓ 12-24 hr post ingestion)
Ivermectin toxicity
Macrolide-p-glycoprotein substrates
Collie/ Herding breeds (MDR1 gene, lack p-glycoprotein)
Ivermectin toxicity MOA
Bind glutamate gated channels → ↑ Cl ions → hyperpolarization of neuron → prevent AP prolongation → paralysis, death of parasite
CS of ivermectin toxicity
CNS (ataxia, hyperesthesia, hypersalivation, muscle fasciculation, seizures, apparent blindness)
Tx for ivermectin toxicity
No antidote
Emesis if less than 2 hrs
AC repeated and cathartic,
Lipid therapy
Highly toxic organophosphates
Disulfoton, coumaphos, famphur, phorate, etc
MOA of organophosphates
OP’s inhibit ACh esterase
Acute syndrome caused by organophosphates
Muscarinic (SLUD, DUMBELS, first to appear)
Nicotinic (m. tremors, muscle tetany, stiffness, paralysis)
CNS (anxiety, restlessness, hyperactivity/ depression, seizures/coma)
Intermediate syndrome caused by organophosphates
Anorexia, diarrhea, generalized weakness, depression and death
Tx for organophosphate toxicity
Stabilize
Atropine sulfate (↓ muscarinic signs)
Pralidoxine/ 2-PAM (control nicotinic signs)
Seizure control
Decontamination (laavage, AC)
Paintball toxicity
Contain osmotically active substances
Loss of fluids in the GI tract → hypernatremia
Paintball toxicity CS
GI signs (local irritation)
CNS signs
Paintball toxicity dx and tx
Monitor serum electrolytes and acid base
Slow infusion of D5W IV (don’t correct hypernatremia to quickly )
Elipidae (snake envenomation)
Coral snakes
Broad bands, night colors, round pupils/ no pit between eyes and small fangs
Crotalidae (snake envenomation)
Pit vipers (rattelsnakes, cottonmouths, copperheads)
Diamond shaped head, elliptical pupils, heat sensing pits, retractable fangs
CS of snake envenomation
Hemorrhage, pain, edema, ecchymosis, tissue damage
Salivation, vomiting, petechia and hypotension
Venom metaloproteinases
Inflammation, hemorrhage and skin damage
Venom hyalonidase/ collagenase
↓ CT and clears glycoside bonds
Venom phospholipid A2
Forms complexes with phospholipids keeping them from clotting activation
Venom fibrinolysins
Major cause of coagulation disorders
Defibrillation- inadequate fribin clot
When should lipid therapy be used
Marijuana, synthetic cannabinoids
NSAIDs (ubuprofen), baclofen, diltiazem, ivermectin like drugs, permethrin cats and cholecalciferol
Lipid therapy MOA
Depends on lipid solubility of drug (should be high)
Liposomes scavenge toxins and carry to organs for metabolism
