Cholecalciferol Flashcards Preview

RUSVM Toxicology 2016 > Cholecalciferol > Flashcards

Flashcards in Cholecalciferol Deck (19)
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1
Q

What is the source for Cholecalciferol?

A

pesticides for the control of mice/rats

2
Q

What are the two sources of exposure to Cholecalciferol?

A

Ingestion of bait

Relay toxicosis

3
Q

What are other sources of Cholecalciferol?

A

Vitamin D feed additives
Poisonous plants
Ingestion of human psoriasis medication containing vitamin D3

4
Q

What are the properties of Cholecalciferol?

A

Insoluble in water

Soluble in most organic solvents/oil

5
Q

What is the order of potency of pharmaceutical Cholecalciferols?

A

Calcitriol

6
Q

Where is Cholecalciferol absorbed from?

A

GI tract

7
Q

Cholecalciferol toxicokintetics

A

Binds to vitamin D binding protein in plasma for transportation to the liver
Metabolized in the liver to 25-hydroxycholecalciferol
Calcidiol is transported to the kidneys and metabolized
Excrete in bile/feces and milk
Undergoes enteroheptic recirculation

8
Q

What is the most potent Cholecalciferol?

A

Calcitriol

9
Q

Where are the highest concentrations of Cholecalciferol found?

A

Plasma
Liver
Kidneys
Fat

10
Q

What are the factors that predispose to Cholecalciferol toxicity?

A

Renal Disease
Hyperparathyroidism
High calcium/phosphorus in the diet

11
Q

Mechanism of Action of Cholecalciferol

A

Causes hypercalcemia and hyperphosphatemia

Increased renal loss of sodium and potassium through competition

12
Q

What does high calcium due to Cholecalciferol toxicity cause in soft tissues?

A

Mineralization - Deposition of calcium in soft tissues

13
Q

How soon do clinical signs of Cholecalciferol toxicosis appear?

A

24-36 hours

14
Q

Clinical signs of Cholecalciferol toxicosis

A
Depends on the tissues affected 
GI: 
Anorexia 
bloody vomiting
abdominal pain 
constipation 
melena
dehydration 
shock 

Renal:
Polyuria
polydipsia
hyposthenuria

Cardiovascular:
Arrhythmias
hypertension

Neurologic: 
Depression 
Weakness
muscle twitching 
seizures
coma 
death
15
Q

What are some lesions seen with Cholecalciferol toxicosis?

A

Hemorrhagic enteritis

Mineralization in tissues

16
Q

What are the clinical pathology findings associated with Cholecalciferol toxicosis?

A

Hypercalcemia
hyperphosphatemia
Elevated serum calcidiol and calcitriol
decreased PTH

17
Q

Treatment of Cholecalciferol toxicosis

A

Decontamination: Emesis, Activated Charcoal
Restricted Calcium/Phosphorus diet
Supportive care

18
Q

How do you treat the hypercalcemia due to Cholecalciferol toxicosis?

A
Saline diuresis
furosemide
sodium bicarbonate
glucocorticoids
Bisphosphonates - \$\$$
19
Q

What is the prognosis for an animal with Cholecalciferol toxicosis?

A

Variable - earlier treatment is best!
Guarded prognosis with severe hypercalcemia
Hematemesis or mineralization = poor prognosis