Glucocorticoids

Question 1

Outline GCs in allergic disease

Answer 1

• appropriate dose
• shortest acting agent for effect
• adjunctive actions (diet, limiting exposures)
• alternative drugs (apoquel, cyclosporine)
• contextualise against costs

Question 2

2 phases of treating I-M disease

Answer 2

• induction of remission

- maintenance of remission

Question 3

What dose of prednisone or prednisolone is needed?

Answer 3

• start with 0.5mg/kg/24 hours and then reduce to 0.5 mg/kg/48 hours

Question 4

Differentiate prednisolone and prednisone

Answer 4

• prednisolone contains hydroxyl group and is active within the body whereas prednisone is inactive in the body but in the body is converted to its active form

Question 5

Outline induction of remission of IM disease

Answer 5

• high dose once daily GC
• dog dose is 2-3mg/kg/24h
• can be a non-divided dose
• only in exceptional circumstances should we start at a dose less than this (almost never)

Question 6

Outline maintenance of remission of IM disease

Answer 6

• centred around alternate day GC therapy with synergistic (non-steroidal) immunosuppressants.

Question 7

Can all dogs have same dose?

Answer 7

No - not a linear relationship between bodyweight and distribution space. Thus dogs >30kg don’t use a mg/kg dose but a mg/m2 dose (90-100mg/m2)

Question 8

What is the steroid dose in cats?

Answer 8

• cats more steroid resistant (variation relates to immunosuppressive not adrenosuppressive effects, may reflect reduced expression, relative to dogs, of glucocorticoid receptors in various organs)
• thus cats have higher dose
• immunosuppressive dose must not be

Question 9

Outline induction of remission protocol

Answer 9

• need a non-divided dose of 3-4mg/kg/24 hours (1.5 times in cats) to INDUCE remission of an I-M dz
• generally for around 10 days, then decrease to 2mg/kg/24 hours for a further 10 days (if adequate clinical response)
• start on alternate day azothioprine or chlorambucil

Question 10

Outline non-steroidal immunosuppressants

Answer 10

• to help with maintenance of remission, start patients on concurrent non-steroidal immunosuppressant at same time:
• DOGS = azothioprine (never in cats, 10-14d to stabilise)
• CATS = chlorambucil (cheap, 2 sizes)

Question 11

How do you maintain remission at day 20?

Answer 11

• same daily dose of prednisolone but given on ALTERNATE days
• will have been on alternate day azothioprine or chlorambucil from day 1:
  > azothiorpine (50mg/m2/48h in dogs)
  > chlorambucil (2mg/CAT/48h)
• prednisolone dose must be

Question 12

How likely is glucocorticoid-induced clinically significant GIT damage?

Answer 12

• allegedly more likely in certain disorders:
• spinal cord trauma/ surgery
• hypovolaemia or anaemia
• azotaemia

Question 13

What gastroprotectants can be used alongside glucocorticoids?

Answer 13

• sucralfate: no effect, at least 2 studies
• H2 antagonists (cimetidine, ramitidine): no effect in one canine study
• omeprazole: no effect in two dog studies
• misoprostol: no effect in at least 4 dog studies

Question 14

Adverse effects - glucocorticoids

Answer 14

• PD/PU (most likely psychogenic PD)
• polyphagia (don’t feed ad lib)
• under dosing –> risk of hypoadrenocorticism

Question 15

Indications - glucocorticoids

Answer 15

• allergic disease
• IM disease
• replacement tx
• neoplasia ( lymphoma, mastocytoma)
• shock (controversial)
• cerebral and spinal cord oedema (controversial)
• profound inflammatory disorders
• hypercalcaemia

Question 16

Outline maintenance of remission protocol

Answer 16

• same daily dose of prednisolone but given on alternate days (2mg/kg/48hours)
• reduce by 25% or 50% every 2-4 weeks
• continue azothioprine or chlorambucil unchanged