Iatrogenic complications of steroid treatments Flashcards
the majority of thyroxine (T4) exists in a state [….].
It has a half life of […]
bound to thyroxine binging globulin (TBG) protein in the plasma (99.98%)
7 days.
compare liothyronine (T3) to T4 thyroxine?
- T3 is more active and more efficient than T4. Less bound to protein and shorter half life (1 day)
- Levels of T3 tend to fluctuate throughout the day.
describe the interplay between t3 and cortisol?
cortisol inhibits conversion of t4 to t3.
t3 inhibits cortisol production.
when would treatment for hypothyroid merit use of T3 rather than standard T4?
-patients with very severe cases of hypothyroid or myxoedema coma (uncommon but life-threatening form of untreated hypothyroidism with physiological decompensation.).
cortisol follows a [….] pattern with peaks occuring before bfast, lunch, and dinner.
Highest peak is approx […] and trough occuring at midnight.
diurnal
8am
midnight
[…] is the inactive form of cortisol
cortisone
cortisol is converted rapidly into cortisone in the [….] as a self-protective measure, avoiding agonist action of cortisol on its […..] receptors.
kidney (11beta-HSD 1 enzyme)
mineralcorticoid
in the […], cortisol is reconstructed from cortisone
liver (via 11beta-HSD 2 enzyme)
cortisol deficiency (primary and secondary) presents with:
- weakness, fatigue, anorexia, nausea, vomiting,
- hypotension and hypoglycaemia
in primary adrenal insufficiency, cortisol deficiency symptoms are coupled with […..] deficiency as well, producing states of hyperkalaemia, hyponatraemia, acidosis and dehydration.
mineralcorticoid.
how should a patient whom you suspect has acute adrenal insufficiency be treated?
cortisol replacement treatment should be initiated immediately while you await further testing. patient will have a very poor prognosis left untreated.
what are the principles of cortisol replacement treatment?
use either cortisol (hydrocortisone) or cortisone.
- divide the dose to mimic physiological time course
- provide extra doses for periods of infection or stress
- supplement with fludrocortisone as needed (help control the amount of sodium and fluids in your body)
how does oral cortisone compare to hydrocortisone (cortisol)?
cortisone bioavailability is poorer but no side effects from well-managed physiological replacement.
bitter tasting but still better than hydrocortisone!
what are some iatrogenic complications of steroid therapy?
in children specifically?
- cushingoid syndrome
- adrenal suppression
- immunosupression (reactivation of latent Tuberculosis)
- peptic ulcers
- osteoporosis
-inhibition of linear growth in children
hypercortisolism can lead to [….]
how might the patient appear?
- weight gain, wasting of muscle, skin and bone.
- hyperglycaemia (from muscle amino acids —> glucose)
- hypertensions (salt retention)
- inhibition of linear growth
- moon face
- red cheeks
- thin skin
- pendulous abdomen with striae
- poor wound healing
how to minimize iatrogenic adrenal suppression, 3 strategies: […]
- allow for acth secretion if possible by morning dosing, alternate day dosing, avoiding long duration dosing
- minimize systemic absorption by choosing alternative modes of administration (ex topical)
- 3rd gen glucocorticoids
what are the advantages of ciclesonide? (3rd gen glucocorticoid)
reduced systemic affects after inhalation:
- pro-drug activated in lungs (won’t cause thrush in the oral cavity)
- lipophilic (retained in tissue)
- low oral bioavailability
- highly protein bound in plasma
T/F: evidence shows glucocorticoids cause peptic ulcers.
FALSE. This is debatable, current studies are confounded by the fact most patients also take NSAID’s a known cause of ulcers.
glucorticoids decrease […] and increase […]
—->enhancing bone resorption and loss of bone mass
OPG
RANKL
kids may potentially lose height by moderate treatment with steroids but this may pale in comparison to disease-induced stunting.
true. too lazy to make card.
