Drug Poisonings Flashcards
Paracetamol = Acetaminophen
Toxicity: v toxic in cats: 50 mg/kg!!, dogs: 150< mg/kg
Metabolism: Paracetamol by CYP450 -> NAPBQ -> covalent binding to liver proteins => necrosis (Hb Fe2+). Alternative: NAPBQ by Glutathione -> merkapturic acid
Instead of NAPBQ: sulfate/glucuronide conjugation.
Clin.signs: Cats (1-2h): vomiting, salivation, lethargy, MetHbaemia (Fe3+) => cherry-chocolate brown blood, haematuria, edema, dyspnoe, death 18-36h. Dogs: vomiting, diarrhea, lethargy, high dose => jaundice, MetHbaemia, haematuria, liver necrosis, death 2-5 days.
Treatment: 1. Elimination: emetics (within 1h), laxatives, activated charcoal.
- Fluids & Electrolyte therapy
- Antidote: Acetylcysteine (-SH donor) first 140 mg/kg IV,PO, then 70 mg/kg every 4h. Or Methionin, SAMe PO. Also Na-sulfate 50 mg/ttkg IV, vit.C 100-150 mg/animal IV,PO (3+ -> 2+).
NSAIDS
Aspirin, Diclofenac, Ibuprofen, Naproxen, Piroxicam, etc. Cats = more sensitive.
Good absorption, metabolism: glucuronic acid conjugation.
Mechanism of effect: local irritation (acid), PGE (stomach, kidney) & TX (platelet aggregation) synthesis inhibition.
Clin.signs: GI ulcers, GI bleeding (bloody vomit, melaena), interstitial nephritis, papilla necrosis (low RBF -> DH, anaesthesia), hepatotoxic, inhibition of platelet aggregation.
Treatment: Antacids, Acid secretion inhibitors: Famotidine, Ranitidine, Omeprazole, Pantoprazole, Sucralfate (coating agent), fluid therapy, Dopamine, NaHCO3 -> alkalize urine.
Xanthine derivatives
Toxicity: Caffeine (200 mg/kg PO), Teophylline, Teobromine (chocolate 100 mg/kg PO -> long T1/2 = 17.5h).
Good absorption, metabolism: liver -> EHC, elimination: urine, bile.
Mechanism of action: ionotrop, chronotrop -> arrhythmia (heart, CNS, kidney).
Clin.signs: vomiting, tachycardia, arrhythmias, hyperactivity, tremors, convulsions -> hyperthermia, brain edema, incr diuresis
Treatment: activated charcoal 2-5g/BWkg 2–3h, emesis, laxatives, anticonvulsions, urine acidifiers (vit.C IV, Methionine PO), propranolol & lidocaine -> arrhythmias
Anticonvulsive drugs
Phenobarbital: for long term control of epilepsy. Toxicosis acute = rare, chronic -> microsomal enzyme induction: hepatotoxic (icterus, ascites), hepatic fibrosis, nodular regeneration. Treatment: infusions, hepatoprotective.
K-Bromide: long term control, long T1/2 -> accumulates (KF), “bromism”, serum [Br]= 3 mg/ml. Treatment: infusions, Furosemide (-> elimination)
Bronchodilators
Beta-2 agonists (Clenbuterole, Salbutamole, Terbutaline) -> treats asthma, chronic bronchitis. Beta 2 -> Beta-1 (<3) dose dependent
Clin.signs: hyperactivity, tachycardia, arrhythmias, hypokalaemia, hypophosphataemia, tremors, convulsions.
Treatment: infusion, Diazepam, Propranolol 0.05 mg/kg IV
Benzodiazepines
Hu sedative -> addiction
Clin.signs: ataxia, icoordination, paradox excitations -> give ACP, but in cats: Diazepam
Treatment: Flumazenil
ACE-inhibitors, Cardiac Glycosides
1.Indications -> CHF, high BP
Symptoms: hypotension, nausea, vomiting, weekness
Treatment: decontamination, fluids
- Digoxin, Digitoxin: +inotrop, -chronotrop. Severe bradyarrhythmia -> ventricular tachycardia!, vomiting, diarrhea.
Therapy: balance hypokalaemia, Lidocaine, Digibind (expensive)
Aminoglycosides
Neomycin (topical), Gentamycin, Tobramycin (parenteral)
Nephrotoxic, Ototoxic
Contraindications: DH, RF. Not more than 7-10 days!!
SID
Clin.signs: acute tubulonephrosis: oliguria/anuria, high creatinine + P, deafness, vestibular signs (nystagmus, head tilt, incoordination)
Treatment: mannit, glucose, dopamine, furosemide
FQs
Cartilage damage
Retina damage
Epileptic seizures
Vomiting, diarrhea
Fluid therapy
SAs
Blood-clotting disorders, crystalluria
Treatment: fluid therapy, vit.K, Alkaligen, Pilocarpin
Antibacterial agents in rodents
Herbivores: Pro & Prebiotics
Anaerobic gut flora, C.Difficile
Prohibited: Lincomycin, Clindamycin, Ampicillin, Amoxicillin, Amoxicillin-Clavulenic acid
Carefully: Narrow spectrum, Penicillins, Cephalosporins, Macrolides
Safe: Fluoroquinolones, potentiated SA
