Toxicology

Question 1

What are the differential diagnoses when considering toxin poisoning?

Answer 1

VITAMIN D
Vascular, Inflammatory/ Infectious, Trauma, Anomalies, Metabolic, Idiopathic, Neoplasia, Degenerative

Question 2

What is LD50?

Answer 2

the amount of a chemical that is lethal to one-half (50%) of the experimental animals exposed to it
aka toxic dose

Question 3

What are the four main principles to think about when considering treatment for a toxin?

Answer 3

Adverse effects of the toxin
Is it acidic or alkalotic?
How it is absorbed
Does it bind to charcoal?

Question 4

What does it mean if a drug is enterohepatically metabolised?

Answer 4

metabolized in the liver > excreted into the bile > passed into the intestinal lumen
then reabsorbed across the intestinal mucosa and returned to the liver

Question 5

What is good practice to monitor/ test for in Toxicology cases? (5)

Answer 5

Temperature- hypothermia is common
Blood glucose
PCV/TP
Coagulation of blood
Biochemistry to test for Renal/ Hepatics

Question 6

When is Emesis indicated?

Answer 6

indicated if the ingestion of the toxin occurred less than 4 hours ago

Question 7

When is Emesis contraindicated?

Answer 7

If patient has neurological changes/ is recumbent
If toxin is caustic (highly acidic or alkaline chemicals

Question 8

What are the risks of Emesis?

Answer 8

Aspiration Pneumonia

Question 9

What is used to induce Emesis?
Give 1 dog & 1 cat example.

Answer 9

Apomorphine IV or Tranexamic acid (dogs)
Xylazine or Medetomidine (cats)- remember its harder to make cats vomit so higher doses may be needed

Question 10

When is a Gastric/ Colonic Lavage indicated?

Answer 10

when ingestion is more than 4 hours ago or when toxin is ingested in large amounts

Question 11

What are the contraindications of a Gastric Lavage?

Answer 11

do not give in cases of Caustic Toxins

Question 12

What are the common complications/ risks of gastric lavages?

Answer 12

Aspiration Pneumonia
Cuffed ET tube
Hypothermia

Question 13

When is activated charcoal treatment contraindicated?

Answer 13

If patient is recumbent, unconscious or having seizures
Substances where charcoal doesn’t bind e.g. alcohol, heavy metals

Question 14

How is Charcoal administered?

Answer 14

Given in food or via a syringe- wait 4 hours or until faeces is black

Question 15

When is Diuresis indicated?

Answer 15

when renal excretion of toxins will occur or if the toxin is nephrotoxic

Question 16

When is Diuresis contraindicated?

Answer 16

if patient is at risk of fluid overload e.g. in cases of cardiac disease , pulmonary disease, anuric (without urine)

Question 17

Over what time period is Diuresis given?

Answer 17

6ml/kg/hr given via IVF over 48-72 hours

Question 18

When is dermal decontamination indicated?

Answer 18

When animal has been externally exposed to toxins e.g. engine oils

Question 19

When are intralipid treatments indicated?

Answer 19

indicated with any lipophilic toxins such as anaesthetics, ivermectin, marijuana

Question 20

What are adverse effects of using Intralipids to treat toxins?

Answer 20

Lipaemia, Pancreatitis, Hypersensitivity