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====Glucocorticoids====
 
====Glucocorticoids====
Corticosteroids, synthesized in the adrenal cortex,
+
Glucocorticoids are
have glucocorticoid (anti-inflammatory and
  −
gluconeogenic) and mineralocorticoid (salt
  −
and water balance) activity. Glucocorticoids are
   
simultaneously the most used and abused drugs in veterinary dermatology. They are cheap, easy
 
simultaneously the most used and abused drugs in veterinary dermatology. They are cheap, easy
 
to administer and highly efficacious but are
 
to administer and highly efficacious but are
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in rapid and profound immunosuppression and
 
in rapid and profound immunosuppression and
 
decreased inflammation.
 
decreased inflammation.
Most quoted doses are for prednisolone (Table 1);
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the dose for other steroids is calculated according
  −
to the relative potency. Steroids also vary in
  −
their mineralocorticoid activity and duration of
  −
activity, but that suppression of the hypothalamicpituitary-
  −
adrenal (HPA) axis may last longer
  −
than the therapeutic effect. Only prednisolone
  −
and methyl-prednisolone are suitable for long term
  −
alternate day dosing as their duration of activity
  −
should leave at least 12 hours for the HPA axis
  −
to recover. The formulation also has an impact:
  −
soluble esters (such as succinates and phosphates)
  −
have a rapid onset and shorter duration of
  −
action; acetates have a moderate onset and
  −
duration; and acetonides and dipropionates are
  −
long-acting depot preparations.
   
Glucocorticoids are highly effective in canine
 
Glucocorticoids are highly effective in canine
 
AD, but must be used with care and, ideally,
 
AD, but must be used with care and, ideally,
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treat flares of inflammation in dogs otherwise
 
treat flares of inflammation in dogs otherwise
 
well controlled on other medication.
 
well controlled on other medication.
 +
 
Topical treatment directs the steroid to affected skin
 
Topical treatment directs the steroid to affected skin
 
and avoids the need for systemic therapy. Topical
 
and avoids the need for systemic therapy. Topical
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localized to relatively hairless skin, pyotraumatic
 
localized to relatively hairless skin, pyotraumatic
 
dermatitis (‘hot-spots’) or in the ears and eyes.
 
dermatitis (‘hot-spots’) or in the ears and eyes.
More potent products containing betamethasone
+
 
etc. can be used once or twice daily initially, but
  −
hydrocortisone is better for long term, alternate day
  −
treatment. Fuciderm® (contains betamethasone) is
  −
a good choice as the gel formulation allows rapid
  −
penetration and drying.
   
Systemic therapy is necessary with more severe
 
Systemic therapy is necessary with more severe
 
or widespread lesions. 0.5-1.0 mg/kg prednisolone
 
or widespread lesions. 0.5-1.0 mg/kg prednisolone
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cannot be altered, nor the hypothalamic-pituitaryadrenal
 
cannot be altered, nor the hypothalamic-pituitaryadrenal
 
(HPA) axis allowed to recover.
 
(HPA) axis allowed to recover.
 +
 
Glucocorticoids will suppress reactions to intradermal
 
Glucocorticoids will suppress reactions to intradermal
 
allergen tests, although the effect on serology is believed to be less marked. It is currently
 
allergen tests, although the effect on serology is believed to be less marked. It is currently
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treatment or with iatrogenic hyperadrenocorticism
 
treatment or with iatrogenic hyperadrenocorticism
 
may need considerably longer withdrawal
 
may need considerably longer withdrawal
times (Figure 5). Glucocorticoids are frequently
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times (Figure 5).
administered to control inflammation during the
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induction phase of immunotherapy. This does not
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Common acute side-effects
appear to affect the response rate although there
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include polyuria and polydipsia. Other acute sideeffects
are no controlled studies.
  −
Adverse effects arise from the glucocorticoid
  −
and mineralocorticoid activity as well as
  −
suppression of the HPA axis and endogenous
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steroid production. Common acute side-effects
  −
include polyuria and polydipsia. The risk of
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these problems developing can be reduced by
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using methyl-prednisolone, which has much less
  −
mineralocorticoid activity. Other acute sideeffects
   
include polyphagia and weight gain
 
include polyphagia and weight gain
 
(which can be managed using a low calorie diet),
 
(which can be managed using a low calorie diet),
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Production of dilute urine is a factor that
 
Production of dilute urine is a factor that
 
contributes to cystitis.
 
contributes to cystitis.
Some of these infections may be clinically
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inapparent, as steroid therapy may mask some of
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the associated inflammation and characteristic
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clinical signs such as pruritus or dysuria.
  −
Because humoral immunity is less affected,
  −
animals can develop adequate antibody titers
  −
following vaccination. For this reason, short
  −
term treatment may be used to control the
  −
clinical signs if cyclosporine has to be withdrawn
  −
because of routine vaccination.
      
====Hydrocortisone aceponate====
 
====Hydrocortisone aceponate====
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