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
2
Q
NSAIDS
A
- COX enzyme inhibitors
- Cox selectivity may influene risk
- cox 1 const: homeostasis
- cox 2 const: inducible, inflammation
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
4
Q
NSAIDS:
organ systems affected
A
- GI
- Kidneys
- Coagulation (platelets)
- Liver
5
Q
Examples of NSAID products
A
- Rimadyl
- Previcox
- Bayer
- Metacam
- Aleve
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
7
Q
NSAIDS
GI PE findings
A
- Inappetance
- vomiting
- diarrhea
- melena
- hematemesis (coffeeground poo)
- hypovolemia
8
Q
NSAIDS
GI lab findings
A
- anemia
- high BUN compared to creatinine
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
- can cause abortion
- misoprostol
- Physical barrier to acid injury
- sucralfate
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
11
Q
Big NSAID offender of bleeding
A
Naproxen/aleve
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
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
- Aim for 3 half-lives of drug
- Charcoal hemoperfusion
- limited availability
- Suitable for larger patients
- > 25kg dog
- Provides large surface area to bind toxin
14
Q
Analgesics:
Acetaminophen
A
- very toxic to cats
- toxic to dogs at high doses
- at risk organs
- liver
- RBCs
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
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
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
- Benzodiazepines (diazepam, valium)
*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
- altered mentation
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
Cardiac medications
* Beta blockers
* Ca channel blockers
* Cardiac glycosides
26
Beta blockers
Physiological effects
downstream effects
* 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
Ca channel blockers (CCB)
Effect of drugs
downstream effects
* Effect of drugs
* Amlodipine
* vascular smooth muscle
* causes hypotension
* Diltiazem
* cardiac muscle
* bradycardia
* Downstream effect
* Amlodipine
* hypotension
* Diltiazem
* bradycardia
* low cardiac output
28
Management
Beta blockers
CCBs
* 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
Cardiac glycosides
* Positive inotrope
* Negative chronotrope
* Foxglove - Digoxin
30
Digoxin tox
Non-cardiac signs
Cardiac signs
* Non-cardiac signs
* GI upset
* Ataxia
* Vision deficits
* Cardiac signs
* bradyarrhythmia
* tachyarrhythmia
* supraventricular
* ventricular
31
Digoxin toxicity management
* Consider concurrent disorders
* electrolyte disorders
* renal dz
* thyroid dz
* Management
* specific arrhythmia treatment
* correct electrolyte abnormalities
* Digibind
32
Drugs that work on autonomic nervous sytem
* PPA (phenylproanolamine)
* Albuterol
33
Phenylpropanolamine (Proin)
* 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
**Albuterol**
**TQ**
* 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
Core mantra toxicology
* Decon
* Antidote
* Symptomatic care
36
Pyrethrin/Permethrin
* From chrysanthemum
* topical flea products, toxic to cats
* Toxicity
* CNS and PNS
* Affects Na channel opening
* Signs
* tremors
* hyperthermia
* seizures
* death
37
Pyrethrin/Permethrin
## Footnote
**TX**
**TQ**
* Decontamination
* clip away wet hair
* wash with dish washing detergent
* Therapeutic options
* **methocarbamol - muscle relaxant for tremors**
* Anti-epileptic medications
* Intralipid
38
Ivermectin
* Activates inhibitory chloride channels in invertebrates
* flaccid paralysis
* death
* toxicity associated with actions on mamallian chloride channels
39
Ivermectin
Neurotox signs
* Ataxia
* Vocalization
* Blindness
* Mydriasis
* Ventalatory failure
40
Ivermectin
TX
* 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
