Toxins-1 meds and pesticides (Lanaux) Flashcards

1
Q

Objectives

A
  • name common medications with toxic potential in small animals
  • recognize toxic effects of pesticides in small animals
  • manage symptomatic and asymptomatic patient affected by toxins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

NSAIDS

A
  • COX enzyme inhibitors
  • Cox selectivity may influene risk
    • cox 1 const: homeostasis
    • cox 2 const: inducible, inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

NSAID COX selectivity

A
  • Older NSAIDS non-selective
    • eg: aspirin
  • Newer NSAIDS may be cox-2 selective
    • eg: carprofen
  • serious effects possible with any NSAID
    • dose is imp
    • hypovolemia inc risk
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

NSAIDS:

organ systems affected

A
  1. GI
  2. Kidneys
  3. Coagulation (platelets)
  4. Liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Examples of NSAID products

A
  1. Rimadyl
  2. Previcox
  3. Bayer
  4. Metacam
  5. Aleve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

NSAIDS:

GI effects

A
  • prostaglandins needed for gastric mucosal health
    • mucus production
    • normal perfusion
  • inhibiting prostaglandins
    • risks GI ulceration
    • slows healing of ulcers from lack of perfusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

NSAIDS

GI PE findings

A
  • Inappetance
  • vomiting
  • diarrhea
  • melena
  • hematemesis (coffeeground poo)
  • hypovolemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

NSAIDS

GI lab findings

A
  • anemia
  • high BUN compared to creatinine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

NSAIDS:

management of GI signs

TQ

A
  • H2 receptor antagonists
    • famotidine
    • pepsid
  • Proton pump inhibitors
    • omeprazole
  • Synthetic prostaglandin analogs
    • misoprostol
      • can cause abortion
        • handle with care
        • client education
  • Physical barrier to acid injury
    • sucralfate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

NSAIDS TX

Supportive care-TQ

SX

A
  • Supportive care depends on case
    • IV fluids if hypovolemic (TQ)
    • red blood cell transfusion if anemic
    • anti-emetics if nauseated
  • Surgery
    • if severe intractable GI bleeding
    • removal of bleeding ulcer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Big NSAID offender of bleeding

A

Naproxen/aleve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

NSAIDS

Other side effects

A
  • Kidneys
    • AKI possible
    • Dialytic and non-dialytic options
    • see AKI notes
  • Platelet dysfunction
    • Aspirin is irreversible inhibitor - 5 days to wear off
    • other NSAIDS are reversible
  • Liver dysfunction
    • less common
    • acute liver injury possible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Management of asymptomatic patient

A
  • GI decontamination
    • induce vomiting
    • multiple doses of activated charcoal - for interohepatic recirc
  • IV fluid diuresis
    • Aim for 3 half-lives of drug
      • about 72 hours
  • Charcoal hemoperfusion
    • limited availability
    • Suitable for larger patients
      • > 25kg dog
    • Provides large surface area to bind toxin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Analgesics:

Acetaminophen

A
  • very toxic to cats
  • toxic to dogs at high doses
  • at risk organs
    • liver
    • RBCs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Acetaminophen

Normal liver metabolism

Cats

A
  • Normal liver metabolism
    • 90% metabolized to non-toxic compounds
    • 5% excreted unchanged in urine
    • 5% converted to toxic NAPQI via CP450
  • Cats limited in glucuronidation
    • limited
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Acetaminophen

NAPQI

Hematological effects

Liver effects

A
  • NAPQI
    • induces oxidative damage
    • binds to -SH groups in RBC and liver
  • Hematological effects
    • methemoglobinemia - chocolate brown gums
    • heinz body anemia
    • hemolytic anemia
  • Liver effects
    • centrilobular necrosis
    • hepatocellular enzymes increase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

cats CS

acetaminophen

A
  • grey chocolate brown gums
  • puffy face
  • usually due to owner medicating animal
18
Q

Acetaminophen DX

A
  • Blood looks dark brown
  • Pulse ox inaccurate
    • methemoglobin distorts SPO2
  • Co-oximetry
    • limited availability
    • measures hemoglobin and methemoglobin
19
Q

Acetaminophen TX

TQ

A
  • N-acetylcysteine (NAC)
    • inc availability of glutathione
    • needed to convert NAPQI to non-toxic conjugates
  • Vitamin C
    • converts methemoglobin back to hemoglobin
  • Methylene blue
    • converst methemoglobin back to hemoglobin
    • can cause a toxicity
  • blood transfusion for normal RBCs to transport oxygen
20
Q

Analgesics: Opioids

A
  • mu opioid receptor activation
    • resp depression
    • dysphoria
    • bradycardia
    • ocular changes
      • mydriasis cats
      • miosis dogs
    • GI changes
      • vomiting
      • constipation

*often combined with acetaminophen to limit risk of abuse

21
Q

Opioids

Antidote

A
  • Naloxone
    • short acting
    • may have to re-dose
  • supportive care
    • fluids
    • ventilation
22
Q

Sedatives and muscle relaxants

TQ

A
  • examples
    • Benzodiazepines (diazepam, valium)
      • flumazenil
    • Barbiturates (phenobarb)
    • Baclofen
      • dialysis may be helpful

*intensive care may be required: mechanical ventilation

23
Q

Serotonin syndrome

A
  • Certain drugs inc serotonin
    • antidepressants
    • opioids
  • CS
    • altered mentation
      • dysphoria
    • autonomic signs
      • bradycardia
    • neuromuscular weakness
24
Q

Serotonin syndrome

TX/antidote

prognosis

A
  • antidote: cyrpoheptadine
    • serotonergic receptor antagonist
    • can give rectally (grind up)
  • Decon if possible
    • vomiting risk if neurologically abnormal
  • Prognosis usually good with appropriate management
25
Q

Cardiac medications

A
  • Beta blockers
  • Ca channel blockers
  • Cardiac glycosides
26
Q

Beta blockers

Physiological effects

downstream effects

A
  • Physiological effects
    • depend on specific adrenergic receptor blocked
      • Beta 1 receptors - mainly heart
      • Beta 2 receptors - airways, blood vessels
  • Downstream effects of beta blockade
    • Bradycardia
    • Poor cardiac contractility
    • Bronchoconstriction
27
Q

Ca channel blockers (CCB)

Effect of drugs

downstream effects

A
  • Effect of drugs
    • Amlodipine
      • vascular smooth muscle
      • causes hypotension
    • Diltiazem
      • cardiac muscle
      • bradycardia
  • Downstream effect
    • Amlodipine
      • hypotension
    • Diltiazem
      • bradycardia
      • low cardiac output
28
Q

Management

Beta blockers

CCBs

A
  • Recent ingestion
    • decon promptly: charcoal
    • IV lipids
  • Symptomatic management
    • Ca salts
    • Atropine
    • Glucagon stimulates Ca release in muscles
    • Insuline effects improve myocardial energetics
    • temporary pacemaker
29
Q

Cardiac glycosides

A
  • Positive inotrope
  • Negative chronotrope
  • Foxglove - Digoxin
30
Q

Digoxin tox

Non-cardiac signs

Cardiac signs

A
  • Non-cardiac signs
    • GI upset
    • Ataxia
    • Vision deficits
  • Cardiac signs
    • bradyarrhythmia
    • tachyarrhythmia
    • supraventricular
    • ventricular
31
Q

Digoxin toxicity management

A
  • Consider concurrent disorders
    • electrolyte disorders
    • renal dz
    • thyroid dz
  • Management
    • specific arrhythmia treatment
    • correct electrolyte abnormalities
    • Digibind
32
Q

Drugs that work on autonomic nervous sytem

A
  • PPA (phenylproanolamine)
  • Albuterol
33
Q

Phenylpropanolamine (Proin)

A
  • Alpha adrenergic receptor agonist
  • Used for urinary incontinence
  • Overdose may cause severe hypertension
    • severe organ damage
      • retinal hemorrhage/detachment
  • Fatality uncommon
  • TX: Symptomatic
    • ventricular arrhythmias: Lidocaine
    • Lanaux give acepromazine
34
Q

Albuterol

TQ

A
  • Beta 2 agonist
    • bronchodilator
    • intracellular translocation K+ via Na-K pump
  • In inhalers for asthma
  • Possible side effects
    • thermal burns in mouth
    • tachycardia
    • severe temp hypokalemia
  • ​TX: symptomatic
    • tachycardia
      • beta-blocker (propanolol)
35
Q

Core mantra toxicology

A
  • Decon
  • Antidote
  • Symptomatic care
36
Q

Pyrethrin/Permethrin

A
  • From chrysanthemum
  • topical flea products, toxic to cats
  • Toxicity
    • CNS and PNS
    • Affects Na channel opening
  • Signs
    • tremors
    • hyperthermia
    • seizures
    • death
37
Q

Pyrethrin/Permethrin

TX

TQ

A
  • Decontamination
    • clip away wet hair
    • wash with dish washing detergent
  • Therapeutic options
    • methocarbamol - muscle relaxant for tremors
    • Anti-epileptic medications
    • Intralipid
38
Q

Ivermectin

A
  • Activates inhibitory chloride channels in invertebrates
    • flaccid paralysis
    • death
  • toxicity associated with actions on mamallian chloride channels
39
Q

Ivermectin

Neurotox signs

A
  • Ataxia
  • Vocalization
  • Blindness
  • Mydriasis
  • Ventalatory failure
40
Q

Ivermectin

TX

A
  • No antidote
  • Benzodiazepines contraindicated
  • Lipid therapy described
    • not great succes for Lanaux
  • Mechanical ventilation if hypoventilation occurs
    • Can have good prog
    • may have to ventilate 1-2 weeks
    • may have to hospitalize 3 weeks
    • bill 20-30K dollars