GC Use In Practice Flashcards
Principles of using GC in Tx allergy
- appropriate dose and shortest acting effective agent
- numerous adjunctive actions that can be undertaken (dietary modification, limiting exposure)
- will have alternative drugs available (apoquel, cyclosporine [lic so must be used - atopica])
- always need to contextualise against costs (steroids cheeeeeap)
Principles of using GCs to Tx immune mediated dz - most common drug used and dose?
- appropriate dose and shortest acting effective agent
> prednisolone [ACTIVE] / prednisone @ 2-3mg/kg/day then lower once in remission
> 2 phases of tx (induction and maintainance of remission) - induction = high dose SID GC Tx
- remission = eod GC and synergistic non-steroidal immunosuppressants
Most likely forms of allergy seen
- dermal
- respiratory
What is most likely to cause iatrogenic hyperadrenocorticism ?
Too LOW a dose of steroid (never get disease under control, continue on medium doses of steroids)
What is the induction dose of prednisolone to Tx immune mediated dz
- 2-3mg/kg/d SID
- Prednisolone has a t1/2 changes with the dose rate, at >1mg/kg half life is >24hrs
- ONLY NEEDS TO BE GIVEN ONCE DAILY! (Compliance better)
> only exeptional circumstances start lower but almost never
> if adverse reactions are going to be seen they will not be dose dependant
How does dose rate of prednisolone change with types of dog?
- larger dogs need relatively lower dose
- dose for body surface area (mg/m2)
> 90-100mg/m2 if dog is over 30kg (~1m^2)
How does dose of prednisolone change for cats?
> steroid resistant
- variation relates to immunosuppressive not adrenosuppressive effects
- may be d/t reduced expression cf. dogs of GC Rs
cats need HIGHER doses cf. dogs
- immunosuppressive dose = 4-5mg/kg
Doses to induce remission in dogs and cats
- non-divided dose ~3mg/kg/day
- 1.5x this in cats
> for 10d then decrease to.. - 2mg/kg/day for further 10d
> then maintain remission
How can maintainance of remission be achieved? How long in will this protocol start?
- start patients on concurrent non-steroidal immunosuppressant at the outset as takes 2w to stabilise
- azathioprine (dogs) 50mg/m2/EOD
- chlorambucil (cats) 2mg/CAT/EOD
> around day 20 - same dose of prednisolone EOD so 2mg/kg/day -> 2mg/kg/EOD
- prednisolone dose must be
Should animals be loaded with azathioprine or chlorambucil?
No
Can cause bad side effects
Summarise induction and maintainance of remission of immune mediated disease
> induction
- non-divided daily dose pred starting at 3-4mg/kg/day
- start EOD azathioprine or chlorambucil
- then with adequate clinical response reduce pred to 2mg/kg/day
maintainance
- same daily dose pred EOD
- reduce by 25% or 50% q2-4w
- continue azathioprine or chlorambucil unchanged
Are gastroprotectant indicated concurrently with steroids? Egs. Of potential gastroprotectants
> no evidence for use
- Sucralfate
- H2 antagonists
- omeprazole
- misoprostol
When is GIT damage as a GC side effect more likely seen?
- more likely in certain disorders
- spinal cord trauma/surgery
- hypovolaemia or anaemia
- azotaemia
Adverse effects of GC
> PUPD
- 1* PD most likely
- remove water if irritating!
- unless has concurrent UTI (d/t immunosuppressive drugs) that will cause a 1* PU
How many calories does average dry and wet food have?
> dry - 400kcal/100g (equivalent to double cream) > wet - 90kcal/100g > meat - 320kcal/100g
