Steroids Flashcards
- If cortisol secretion in the dog is 1 mg/kg/day and prednisolone is 5X as potent as cortisol, give the doses for: a) replacement therapy b) anti‐inflammatory therapy c) immune suppression.
- Replacement therapy = 0.2 mg/kg/day
- Anti-inflammatory therapy = 1mg/kg/day
- Immune suppression = 3 mg/kg/day
- How do the glucocorticoid requirements of an Addisonian patient increase during stressful situations?
• Animals will need supplemental glucocorticoids beyond maintenance doses in times of stress
o Give 3x dose if boarding/groomer/company
o Because they do NOT have the Pituitary-Adrenal Axis, so you must act as that axis for them
- What criteria are used to make dosage adjustments in Addison’s for the
• Mineralocorticoid
• Glucocorticoid
• Mineralocorticoid = based on serum Na and K
• Glucocorticoid = based on clinical signs
o Inappetence, vomiting, diarrhea, depression = increase the dose
o Peripheral edema, PU/PD, other signs of hyperadrenocorticism dose-decrease dose
- Name the two drugs and their routes of administration used in Addison’s disease to supplement mineralocorticoids. (I am not asking for prednisolone.)
- Fludrocortisone (Flurinef) – given orally, some glucocorticoid activity
- Desoxycorticosterone pivalate (DOCP) – given SQ, devoid of glucocorticoid activity
- What glucocorticoid is similar in potency and duration to prednisolone, but lacks its mineralocorticoid activity?
• Triamcinolone
- Name a steroid known to induce surfactant production in the bovine fetus.
• Prednisolone
• Isoflupredone
• Cortisol induces surfactant production from alpha 2 receptor cells at a specific time of gestation
• Can give injection of dexamethasone 36-48 hours before c-section so surfactant is produced and lungs can expand upon birth
o Dex is more lipid soluble so crosses placenta better
• Methylprednisolone doesn’t cross placenta like dexamethasone so won’t induce surfactant production
- Classify injectable steroids as repository versus suitable for iv use. (Based on name of formulation. e.g., a succinate versus acetate.)
• IV Nonrepository:
o Water soluble, can be given IV
o Duration controlled by biological half-life
o Sodium succinate and Sodium phosphate
E.g. prednisolone sodium succinate, dexamethasone sodium phosphate
• IM Repository (Depo)
o Water insoluble, given IM
o Duration controlled by rate of absorption (usually lasts 2-4 weeks)
o Acetate, Acetonide, Pivalate
E.g. methylprednisolone acetate (DepoMedrol), triamcinolone acetonide (Vetalog), and flumethasone pivalate (Locorten)
- What effect does the ester formulation have on use of an oral steroid?
• NO EFFECT; Duration of an oral steroid is due to its biological half-life and not the formulation
- Compare and contrast the benefit of steroid therapy in acute spinal cord trauma versus acute brain trauma.
• Traumatic injuries to the spinal cord (but not brain) can be minimized by prompt treatment with high dose methylprednisolone
o mechanisms other than phospholipase inhibition may be involved
o though steroids can inhibit vasogenic edema, most traumatic CNS injuries develop cytotoxic
• Edema that is nonsteroid responsive.
o appears that neuroprotective mechanisms do not revolve around minimization of edema
- Which steroid(s) has shown the greatest utility (most evidence) in minimizing spinal cord trauma injury? Include the formulation of the steroid(s).
• Most work has used high dose of methylprednisolone sodium succinate.
o to be effective, the drug must be given promptly
after 8 hours there is no benefit to giving steroids
o give 30 mg/kg IV immediately. Various regimens follow with additional doses
o neurologist dependent!!
• Methylpred has be shown to improve neurologic status and survival to discharge when administered during CPR
- What are the types of cerebral edema and which are steroid responsive? Indicate the most common cause of each type of brain swelling.
• Interstitial cerebral edema: hydrocephalus
o Responds to steroids help by decreasing CSF production decreasing pressure
• Vasogenic cerebral edema: some brain tumors and infection
o responds to steroids (slows replication and to decrease edema)
• Cytotoxic cerebral edema: following trauma
o NOT steroid responsive (osmotic diuretics, etc instead)
- Explain why steroids have been hypothesized to predispose to laminitis in horses and which steroids have been most commonly implicated.
• Glucocorticoids may not cause it on its own, but they might only increase the risk of developing laminitis when other causative factors are present or may exacerbate existing laminitis
• If it occurs, the mechanism is unknown but may be due to sensitization of alpha receptors in the hoof wall
• Steroids:
o Triamcinolone
o Dexamethasone (and related flumethasone, betamethasone)
- Name two steroids with the lowest risk of inducing parturition in the cow in late pregnancy.
• Prone to abortion/induction of parturition from certain steroids in the last half of gestation and especially in the last month of gestation
o Prednisolone & isoflupredone
- Which steroid is most commonly used to induce partition/abortion in cows?
• C16-methylated Dexamethasone (betamethasone, flumethasone)
- At one time dexamethasone was a commonly used inhaled steroid. Why has it been largely replaced by fluticasone?
• Fluticasone is VERY water insoluble, it undergoes the first pass effect and never reaches systemically
o Not absorbed into the central circulation and therefore have few if any systemic side-effects
• Dexamethasone is more soluble, meaning that it would impart systemic effects.
- Not including reproductive effects or Cushing’s syndrome, name the six contraindications one should consider before administering a glucocorticoid.
• Gastrointestinal ulceration
o Steroids may result in ulcer development or aggravate an existing ulcer
o May want to add an acid suppressor to the regimen
• Systemic mycoses
o Diseases are held in check by cell mediated immunity which are inhibited by steroids (mycobacterial infections inhbited as well)
o Consider using steroids if animal is on an antifungal agent first
• Situations where rapid healing is desired (slow wound healing)
o Intestinal resectin and anastomosis
o Steroids delay wound healing and should be avoided because dehiscence may result
o Short-acting water soluble steroid if steroid must be used
• Abortion and birth defects (not in horses or sheep, dogs are also difficult 10days)
o Gives a high risk for retained placenta
o Will decrease milk production (important for dairy cattle)
o Birth defects may result if steroids are sed in the first trimester
o High dose steroids in the pregnant bitch can cause fetal death and reabsorption in the first half of gestation or abortion thereafter
o Catlle are most prone to steroid-induced abortion (prone from mid-gestation on but especially during last month of gestation)
• Procoagulant effects
o Higher risk for thromboembolism pulmonary thromboembolism
o Animals with hyperadrenocorticism are predisposed to sudden death from thromboembolism occurs with exogenous steroid administration (steroids should be avoided)
o Immune mediated hemolytic anemia patients commonly die from thromboembolism since immune disease requires the use of steroids (combine with an anticoagulant drug)
• Pancreatitis
o Animals may develop pancreatitis while using steroids (risk factor)
o Association is week so still use in immunosuppressed patients if needed (avoid in animals with history of pancreatitis or prone to it)
• Diabetes mellitus
o Anti-insulin effect (difficult regulation of the diabetic insulin regulation but not impossible)
o Cats treated with Depo-Medrol repeatedly are at high risk for developing diabetes (can get into remission, consider oral pred for repeat kitty allergy offenders)
- Classify the common steroids as to whether they are appropriate for alternate‐day use.
• Only short acting or intermediate acting steroids (prednisolone, methylprednisolone, and triamcinolone) can be given as alt-day doses. Dexamethasone is NOT ideal because it is long-acting.
o Prednisolone = most commonly used
o Methylprednisolone = used to minimize sodium and water retention
o Hydrocortisone = rarely used systemically in vet med
o Triamcinolone = used to minimize sodium and water retention
- What advantages does alternate‐day steroid use provide over daily use?
- Less immunosuppression
* Less pituitary-adrenal axis suppression
- 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?
- Dogs: Morning – cortisol surge naturally in the morning (Diurnal rhythm), trying to mimic this
- Cats: No diurnal rhythm (perhaps nocturnal) time of administration not important so can give at any time point during day
- What effect do glucocorticoids have on excretion of calcium?
• Enhance renal elimination of calcium (effective in tx of hypercalcemia)
- In which species is prednisone a poor choice for a glucocorticoid and why?
Cats and Horses Do NOT absorb/convert prednisone well
- How do cats differ from dogs relative to:
• The risk of causing iatrogenic Cushing’s. • The usual dose required to achieve an equivalent effect. • Risk of induced diabetes mellitus
- The risk of causing iatrogenic Cushing’s. Very low risk, dogs at higher risk for iatrogenic Cushing’s
- The usual dose required to achieve an equivalent effect. Cats require 2x dose as a dog for same anti-inflammatory effect
- Risk of induced diabetes mellitus Cats at greater risk
- Identify the glucocorticoids discussed that also have significant mineralocorticoid effects.
- Hydrocortisone
* Prednisolone
- 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?
• Cell-mediated immunity (systemic mycoses and mycobacteria)
Fungal
