Glucocorticoids

Question 1

If cortisol secretion in the dog is 1 mg/kg/day and prednisolone is 5X as potent as cortisol, what is the dose for replacement therapy?

Answer 1

1/ 5= 0.2 mg/kg/day of prednisiolone (1 mg/kg/day of cortisol secretion divided by 5)

Question 2

If cortisol secretion in the dog is 1 mg/kg/day and prednisolone is 5X as potent as cortisol, what is the dose for anti-inflammatory therapy?

Answer 2

Begin therapy at 5 x the normal cortisol secretion, then taper to the lowest dosage that control the symptoms
5 x 1/mg/kg/day= 5 mg/kg/day of cortisol
A dog would need 1 mg/kg/day of pred

Question 3

If cortisol secretion in the dog is 1 mg/kg/day and prednisolone is 5X as potent as cortisol, what is the dose for immune suppression?

Answer 3

Begin therapy at 16 x normal cortisol secretion, then taper to the lowest dosage that controls the symptoms
16 x 1 mg/kg/day = 16 mg/kg/day or cortisol
Since pred is 5x as potent, you would need 3 mg/kg/day of pred

Question 4

How do the glucocorticoid requirements of an Addisonian patient increase during stressful situations?

Answer 4

Supplemental glucocorticoids are needed in stress. You’ll give 3x the dose if boarding/groomer/company

Question 5

What criteria are used to make dosage adjustments in Addison’s for the mineralocorticoid?

Answer 5

Dosage adjustments are made based on serum Na and K concentrations

Question 6

What criteria are used to make dosage adjustments in Addison’s for the glucocorticoid?

Answer 6

Dosage adjustments are made based on clinical signs
Inappetence, vomiting, diarrhea, depression –> increase dose
Peripheral edema, PU/PD, other signs of hyperadrenocorticism dose –> decrease dose

Question 7

Name the two drugs and their routes of administration used in Addison’s disease to supplement mineralocorticoids.

Answer 7

DOCP (desoxycorticosterone pivalate) is given once a month SQ
Fludrocortisone is given orally

Question 8

What glucocorticoid is similar in potency and duration to prednisolone, but lacks its mineralocorticoid activity?

Answer 8

Methylprednisolone

Question 9

Name a steroid known to induce surfactant production in the bovine fetus.

Answer 9

Dexmethasone will stimulate the type 2 alveolar cells to produce surfactant in the fetus as it crosses the placenta better than prednisolone

Question 10

Classify injectable steroids as repository versus suitable for iv use. (Based on name of formulation. e.g., a succinate versus acetate.)

Answer 10

IV nonrepository: Succinate and phosphate

IM repository: Acetate, acetonide, and privalate

Question 11

What effect does the ester formulation have on use of an oral steroid?

Answer 11

There is a possible link between oral use and liver cancer

Question 12

Compare and contrast the benefit of steroid therapy in acute spinal cord trauma versus acute brain trauma.

Answer 12

Spinal cord trauma

• –injuries can be minimized by prompt treatment with high dose methylprednisolone
• –There is no benefit if given after 8 hours
• –Give 30 mg/kg IV immediately
• –Methylprednisolone has been shown to improve neurologic status and survival to discharge when administered during CPR

Brain trauma
—Injuries cannot be minimized by prompt treatment with high dose methylprednisolone

Question 13

Which steroid(s) has shown the greatest utility (most evidence) in minimizing spinal cord trauma injury? Include the formulation of the steroid(s).

Answer 13

Methylprednisolone sodium succinate
Formulation:
Water soluble
Can be given IV
Duration is controlled by biological half-life (12-36 hours)

Question 14

What are the types of cerebral edema and which are steroid responsive? Indicate the most common cause of each type of brain swelling

Answer 14

Interstitial cerebral edema

• —Occurs in hydrocephalus
• —Steroids help by decreasing CSF production

Vasogenic cerebral edema

• —Occurs in some brain tumors and infections
• —Responds to steroids

Cytotoxic cerebral edema

• —Occurs following trauma
• —Not steroid responsive

Question 15

Explain why steroids have been hypothesized to predispose to laminitis in horses and which steroids have been most commonly implicated.

Answer 15

Evidence is weak
If an animal has had any predisposing factors to laminitis, steroids may increase the risk
Steroids/glucocorticoids sensitize the alpha receptors and the lamina in the hoof is a type of skin that has alpha receptors
Alpha receptors make the blood vessels constrict

The most commonly implicated are triamcinolone, dexamethasone, (and related flumetasone, and betamethasone)

Question 16

Name two steroids with the lowest risk of inducing parturition in the cow in late pregnancy.

Answer 16

Prednisolone (probably not used), isoflupredone

Meloxizam

Question 17

Which steroid is most commonly used to induce partition/abortion in cows?

Answer 17

Dexamethasone, betamethasone, flumethasone

Question 18

At one time dexamethasone was a commonly used inhaled steroid. Why has it been largely replaced by fluticasone?

Answer 18

Dexamethasone had some systemic absorption and the side-effects were undesirable. The newer inhaled steroids (fluticasone) are not absorbed into the central circulation and therefore have few if any systemic side-effects

Question 19

Not including reproductive effects or Cushing’s syndrome, name the six contraindications one should consider before administering a glucocorticoid.

Answer 19

Gastrointestinal ulceration
Systemic mycoses
Delayed wound healing
Pancreatitis
Diabetes mellitus
Mycobacterial infections

Question 20

Classify the common steroids as to whether they are appropriate for alternate‐day use.

Answer 20

Any nonrepository steroid can be used early on, but only sort or intermediate acting steroids are appropriate for alternate day use
Appropriate:
Hydrocortisone
Prednisolone
Methylprednisolone
Triamcinolone

Inappropriate:
Dexmethasone
Betamethasone
Flumethasone

Question 21

What advantages does alternate‐day steroid use provide over daily use?

Answer 21

Less immunosuppression

Less pituitary-adrenal axis suppression

Question 22

If dogs are given once daily steroids, all other considerations being equal, what time of day should the dose be given and why? What about the cat?

Answer 22

Dogs have a diurnal rhythm, so they have a surge of cortisol in the mornings
Cats do not have a diurnal rhythm because they are possibly nocturnal

Question 23

What effect do glucocorticoids have on excretion of calcium?

Answer 23

Glucocorticoids enhance the renal elimination of calcium

This is used to our advantage when we are treating hypercalcemia

Question 24

In which species is prednisone a poor choice for a glucocorticoid and why?

Answer 24

Cats and horses: They do not absorb/convert prednisone well- use prednisolone
Cattle: Use prednisolone to reduce the risk of abortion or inducing parturition

Question 25

How do cats differ from dogs relative to the risk of causing iatrogenic Cushing’s?

Answer 25

Repeated injections cause cushing’s in dogs, but not cats

Question 26

How do cats differ from dogs relative to the usual dose required to achieve an equivalent effect?

Answer 26

Cats require 2 times the dose as a dog for the same anti-inflammatory effect

Question 27

How do cats differ from dogs relative to the risk of induced diabete mellitus?

Answer 27

Cats treated with Depo-Medrol repeatedly are at high risk for developing diabetes

Question 28

23. Identify the glucocorticoids discussed that also have significant mineralocorticoid effects

Answer 28

Hydrocortisone

Prednisolone

Question 29

24. What branch of immunity is most severely impaired by steroid use? What group of infectious agents does this immunosuppression have the greatest clinical impact on?

Answer 29

Cell-mediated immunity

Systemic mycoses. Also true for mycobacterial infections