endocrine Flashcards
acromegaly lab first line diagnostic test
Elevated insulin like growth factor (IGF-1)
Pituitary adenoma stimulation tests
triple bolus test of hypopituitarism
- Rapid IV infusion of insulin, GnRH, and TRH
- Insulin bolus leads to hypoglycemia which increases GH and ACTH/cortisol
- GnRH IV push increases LH and FSH
- TRH IV push increases TSH and PRL
lab increased in Grave’s disease
thyroid stimulating IMMUNOGLOBULIN (TSI)
HLA associations with Graves
HLA-B8 and HLA-DR3
hyperparathyroidism is usually caused by what?
parathyroid adenoma
lab for adrenal hyperfunction
24 hour urinary free cortisol
Serum ACTH is high or low in what conditions
high - primary adrenal insufficiency
low - secondary “ “
Tx for adrenocortical insufficiency (addison’s disease)
- IV normal saline or D5W in large volumes
- Hydrocortisone 100mg IV every 6-8 hours for 24 hours, then taper
Electrolyte findings in adrenocortical insufficency (addisons)
hyponatremia
hyperkalemia
metabolic acidosis
lab findings in adrenocortical insufficency (addisons)
- ACTH stimulation test shows NO inc in cortisol
- electrolyte findings (low Na, high K)
- high ACTH
- low urinary cortisol
- fasting hypoglycemia
Waterhouse-Friderichsen syndrome and anticoagulation therapy (neisseria mening) can cause what
acute adrenocortical insufficiency (adrenocortical hypofunction)
Cushing’s disease is excess cortisol due to what
ACTH-secreting pituitary adenoma
Labs for Cushing’s disease
- elevated 24 hour urinary cortisol
- increased cortisol after low dose of Dexamethasone suppression test
- decreased cortisol after HIGH dose dexamethasone
- subnormal total lymphocytes, low eosinophils, hyperinsulinemia, Abnormal OGTT, increased serum Ca+
what is hyperaldosteronism
- inc aldosterone secretion leading to DIASTOLIC HTN WITHOUT EDEMA, decreased renin secretion, and metabolic alkalosis (b/c aldosterone increases H+ secretion)
Hyperaldosteronism is typically caused by
Conn’s syndrome (aldosterone-producing adrenal adenoma)
pheochromocytoma classic triad Sx
- episodic pounding H/A
- palpitations
- drenching sweats
food ingredient that can trigger pheochromocytoma Sxs
tyramine
labs for pheochromocytoma
- urine catecholamines (increased VMA, HVA)
- inc plasma metanephrines (MOST SENSITIVE)
- plasma catecholamines (inc plasma epi unsuppressed by clonidine is DIAGNOSTIC)
- hyperglycemia
- CT abdomen
diagnostic medication for pheochromocytoma
Clonidine (epi is unsuppressed)
Type 1 DM HLA
HLA DR3 and DR4
pancreatic tumor (insulinoma) labs/imaging
- increased serum insulin and C-peptide
- Abdominal US
- CT scan (not sensitive)
Multiple Endocrine Neoplasia 1 (MEN I) common Sxs
- kidney stones, stomach ulcers, Sxs of hyperparathyroidism and insulinoma
MEN II common Sxs
- Sxs related to medullary thyroid cancer (secretes calcitonin), hyperparathyroidism, or pheochromocytoma, scaly skin rash
MEN I signs
- gastrinoma (PUD, esophagitis)
- glucagonoma (rare)
- hyperparathyroidism (nephrolithiasis, bone abnormalities, MSK complaints)
- pituitary tumor (HA, prolactinoma, acromegaly)
MEN II signs
- medullary thyroid cancer (goiter, LAD)
- pheochromocytoma (elevated BP, classic triad of pounding HA, palpitations, sweats)
MEN I labs/imaging
- elevated serum gastrin (after IV secretin- for gastrinoma)
- elevated PTH (hyperparath)
- examine GH, prolactin, blood glucose
- MRI
MEN II labs/imaging
- calcitonin levels (medullary thyroid carcinoma)
- Serum Ca and PTH levels (hyperpara)
- urine catecholamines, VNA, metanephrines (pheochromocytoma)
- CT or MRI on adrenals
Tx of MEN I
PPI for gastrinoma
Bromocriptane (dopamine agonist) to suppress prolactin
Tx of MEN II
surgery
- alpha blocker for pheochromocytoma pre-operatively
- hydration for hypercalcemia, consider calcitonin, IV bisphosphonates for hypercalcemia
rehydration Tx of ketoacidosis from DM
- 1 L/hr normal saline (0.9%NaCl) in first 2 hours
- then 300-400 ml/hr 0.45 NS
- when BG reaches 13.9, switch to D5W to maintain blood glucose
when to add HCO3 for ketoacidosis rehydration
add to .45%NS if pH < 7 or Pt has hypotension, arrythmia, coma
what drugs can mask signs of and prolong recovery from hypoglycemia
beta blockers
what drugs can increase insulin requirements
thiazides and steroids
what can decrease insulin requirements
alcohol, most NSAIDs, sulfonylureas, warfarin
Pioglitazone may reduce levels of what
OCPs
what drug can increase levothyroxine requirement
estrogens
what drug can decrease levothyroxine absorption
Bile acid sequestrants
Lugols solution interacts with what drugs
- ACE-I’s
- ARBs
- diuretics
- lithium
- drugs with potassium in them
Isotretinoin decreases efficacy of what
microdosed progesterone (use 2 forms of contraception)
Isotretinoin may increase risk of bone loss/osteoperosis with what drugs
phenytoin, steroids
Terbanafine (antifungal) increases effects of what drugs
SSRIs, Beta blockers, MAOI, warfarin; increases hepatotoxicity with hepatotoxic drugs
What herb interacts with furosemide
Licorice (may cause rapid potassium loss)
what drug does nitroglycerin increase effect of
sildenafil (viagra)
antiHTN effect of HCTZ may be decreased with what drugs
steroids, NSAIDs
HCTZ may enhance nephrotoxicity of what drug
NSAIDs
HCTZ combined with what drugs may cause orthostatic hypotension
opioids, barbituates, alcohol
Beta blockers decrease effect of what hormone
dopamine
carbamazepine shortens half life of what drug
doxycycline
carbamazepine reduces tolerance of what
alcohol
carbamazepine reduces efficacy of what
OCPs