Steroid Pharmacology Flashcards
What test can be used to detect secondary adrenal insuficiency (i.e. decreased pituitary ACTH production in the setting of low cortisol)
Cosyntropin (synthetic ACTH) stimulation test
250 mcg given IV and recheck cortisol
in 60 minutes (levels should be greater than 18-20)
What levels of cortisol preclude diagnosis of secondary adrenal insuficiency?
> 20
What differentiates primary vs secondary adrenal insuficiency?
Hyperpigmentation not present because ACTH
levels are not elevated
Dehydration does not occur because lack of ACTH leaves aldosterone synthesis intact
hypotension is less prominent - cortisol causes increase and sensitization in alpha-adrenergic receptors => decreased cortisol causes hypotension
**BUT ==> with secondary lack of ACTH leaves aldosterone intact and thus compensates of loss of cortisol
Hyperkalemia does not occur - also because aldosterone intact
What are the symptoms of primary adrenal insuficiency?
weakness fatigue orthostatic hypotension muschle aches weight loss GI disturbances Sugar/salt cravings
T/F Hypoglycemia is more common in secondary AI than
primary
true
T/F neither cortisol or cortisone is used for treatment of adrenal insufficiency
true
T/F normal response to cortisol stimulation test (administration of ACTH analogue and observation of cortisol rise) precludes diagnosis of primary adrenal insufficiency but leaves the possibility of secondary insufficiency that began within the past couple weeks
true
T/F first step in treatment of adrenal insufficiency is infusion of large volume NS or 5%DexNS
true
T/F second step in treatment of adrenal insufficiency after saline infusion (given to normalize hypotension and electrolite imbalances) is dexamethazone i.v. (4mg)
true
Why is dexamethazone the drug of choice for treatment of adrenal insufficiency (2 reasons)?
1) long half-life (12-24hrs)
2) doesn’t interfere with cortisol stimulation testing to determine primary vs secondary
T/F mineralcorticoids are useful for acute treatment of adrenal insuficiency
false
Mineralocorticoids alone are not useful acutely as it takes several days for its sodium retaining effects to manifest and sodium can be replaced adequately by saline
What is the drug of choice for treatment of adrenal insufficiency after normalizing hypotension and electrolyte balance and giving dexamethazone for initial acute rescue of glucocorticoids?
Fludrocortisone - glucocorticoid with more potent mineralcorticoid activity
What is the drug of choice for mineralcorticoid replacement (maintenance therapy) ?
fludrocortisone oral (0.1 mg/day) with libral salt intake
What is the drug of choice for glucocorticoid replacement (maintenance therapy) ?
oral dexamethazone 0.5 mg or prednisone 5 mg at BEDTIME
Hydrocortizone may be used but has to be given twice, larger dose in morning than afternoon
How does a patient with adrenal insufficiency typically present clinically?
shock (in a previously undiagnosed patient who is subjected to stress)
Other non specific symptoms: anorexia, nausea,
vomiting, abdominal pain, weakness, fatigue,
lethargy, confusion, or coma.
Abdominal tenderness on deep palpation without
localizing signs is common, unknown cause.
Fever often present, may or may not have cause.
Those with long standing AI may have
hyperpigmentation or weight loss.
