Addison's Disease Flashcards
Which hormones are released from the anterior pituitary?
- LH
- GH
- ACTH
- TSH
- MSH
- Prolactin
- FSH
Which hormones are released from the posterior pituitary?
- Oxytocin
2. ADH
What are the 3 layers of the adrenal cortex from superficial to deep?
- Zona glomerulosa
- Zona fasciculata
- Zona reticularis
What is released from the zona glomerulosa?
Mineralocorticoids (aldosterone)
What is released from the zona fasciculata?
Glucocorticoids (cortisol)
What is released from the zona reticularis?
Anabolic and sex hormones
What is released from the adrenal medulla?
Catecholamines (epinephrine and norepinephrine)
What is the base molecule for aldosterone, cortisol, and estradiol?
Cholesterol
Hypoadrenocorticism is a deficiency in what?
- Aldosterone
2. Cortisone
Hyperadrenocorticism is an excess of what?
Cortisone
Hyperaldosteronism is an excess of what?
Aldosterone
What 4 changes trigger the secretion of aldosterone?
- Hyponatremia
- Hypotension
- Hypovolemia
- Hyperkalemia
What are aldosterone’s 2 main actions on the body?
- Renal conservation of Na
2. Renal excretion of K
From where is cortisol secreted?
Zona fasciculata
What is cortisol secreted in response to?
ACTH
What are the metabolic functions of glucocorticoids?
- Increase gluconeogenesis
- Increase fatty acid mobilization
- Decrease protein synthesis
How do glucocorticoids affect appetite?
Increase appetite
What are serum glucose levels with addison’s and cushing’s?
Addison’s = hypoglycemia
Cushing’s = hyperglycemia
What are blood pressures associated with addison’s and cushing’s?
Addison’s = hypotension
Cushing’s = hypertension
What is the most typical presentation of a dog with addison’s disease?
- Female
- Medium/large breed
- Mixed breed
- Young (2-7 years of age)
Which 4 dog breeds are genetically predisposed to addison’s?
- Standard poodle
- Portuguese water dog
- Nova scotia duck tolling retriever
- Bearded collie
What are some of the vague clinical signs associated with addison’s?
- Weight loss
- Vomiting & Diarrhea
- Polyuria
- Poor appetite
- Lethargy
- Weakness
What would you find on physical exam of a dog with addison’s disease?
- Bradycardia
- Dehydration
- Poor peripheral pulses
- Hypothermia
- Melena/hematochezia
What would you find on CBC associated with addison’s disease?
- LACK of stress leukogram
- Eosinophilia
- Lymphocytosis
What would you find on a chemistry profile associated with addison’s disease?
- Hyperkalemia
- Hyponatremia
- Hypercalemia
- Azotemia
- Hypoglycemia
Explain the sodium:potassium ratio associated with addison’s disease…
Na:K
<24:1
Other than addison’s disease, what are 5 differentials for a low Na:K ratio?
- Renal failure
- Severe GI disease
- Third space fluids (ascites, pleural effusion)
- Late pregnancy
- Akitas (K+ in RBCs)
What would you see on ECG with hyperkalemia?
- Bradycardia
- Loss of P wave
- Peaked T wave
- Wide QRS
- Shortened QT interval
Explain the protocol for the ACTH stimulation test.
- Collect baseline cortisol level
- Inject ACTH
- Collect 1 hour cortisol level
What is the typical result to the ACTH stimulation test when the animal has addison’s disease?
Flatline
A basal cortisol of greater than ___ ug/dL helps rule-out hypoadrenocorticism.
> 2 ug/dL
If it is clinically necessary to administer corticosteroids prior to performing an ACTH stimulation test, which medication should be used?
Dexamethasone
Prior to performing an ACTH stimulation test, a patient must be weaned off prednisone because it will be measured as what?
Cortisol
The treatment of choice for hypoadrenocorticism is hormone replacement. Which drug can be used to replace glucocorticoids?
Prednisone
What is the physiologic dose of prednisone on which a patient is typically started?
0.1 - 0.22 mg/kg/day
Which drug provides both mineralocorticoid and glucocorticoid replacement?
Oral Florinef
What does Percoten replace within the body?
Only mineralocorticoids
What is the dosage protocol for Percorten?
2.2 mg/kg IM or SC every 25-31 days
Part of the monitoring and long-term maintenance of an addisonian patient involves decreasing the Percorten dose from what to what?
2.2 mg/kg –> 2.0 mg/kg –> 1.8 mg/kg
Also part of the monitoring and long-term maintenance of an addisonian patient involves increasing the dosing interval from what to what?
25 days –> 26 days –> 27 days –> 28 days –> 29 days –> eventually 30 days
What is the MOST important factor in long-term response to therapy in an addisonian patient?
Client education
An addisonian crisis is the result of what 5 physiologic abnormalities?
- Hypotension
- Dehydration
- Hypoglycemia
- Hyponatremia
- Hyperkalemia
What is the most life-threatening component of an addisonian crisis?
Vascular collapse and shock
What is the most important component of therapy for an addisonian crisis?
IV fluid replacement
How do the doses of Dexamethasone and Prednisone differ?
The prednisone dose is 7 times that of Dexamethasone
What is a “typical” addisonian?
Deficient in glucocorticoids and mineralocorticoids.
What is an “atypical” addisonian?
Deficient in glucocorticoids alone.
What is the therapy for an “atypical” addisonian?
Glucocorticoid replacement
