Endocrine Flashcards
Graves disease
Autoimmune disorder where thyroid-stimulating antibodies directed at thyrotropin receptors mimic TSH and stimulate T3 & T4
Hyperthyroid
Elevated T4, decreased TSH
Hyperthyroid disorders
Graves
Pituitary adenoma
Toxic adenoma
Toxic multinodular goiter (Plummer)
Painful subacute thyroiditis
Drug induced (thyroid hormone, amiodarone)
Propylthoiuracil MOA, dosing, BBW, ADR
MOA: Inhibits iodination and synthesis of thyroid hormone; blocks T4>T3 conversion in periphery
50-150mg TID
BBW: hepatotoxicity
ADR: rash, arthralgia/lupus-like, fever, agranulocytosis
Methimazole MOA, dosing, ADR
MOA: Inhibits iodination and synthesis of thyroid hormone
DOC for Graves
10-30mg daily
ADR: Embryopathy risk in first trimester, rash, arthralgia/lupus like, fever, agranulocytosis
Methimazole, PTU onset, treatment duration (Graves)
Max effect 4-6 months
Treatment may be 12-18 months
Iodines & Iodides MOA, efficacy
Lugol’s solution, saturated solution of potassium iodide, potassium iodide tablets
MOA: inhibit release of stored thyroid hormone; decreases size of gland before surgery
Efficacy of 7-14 days - use prior to surgery, after ablative therapy, or acutely in thyroid storm
Teprotumumab
Insulin-like growth factor-1 receptor inhibitor
Use for thyroid eye disease
IV route
Thyroid storm treatment
1) Propylthiouracil 500-1000mg load
2) Iodide therapy 1 hr after PTU load to block hormone release
3) Hydrocortisone 300mg IV load
3) then PTU 250mg q4h, hydrocortisone 100mg q8h
4) Propranolol or esmolol
5) APAP for fever - do not use NSAID
Hashimoto
Autoimmune-induced thyroid injury resulting in decreased thyroid secretion (antibodies: antithyroid peroxidase, antithyroiglobulin)
Hypothyroid
Elevated TSH, low T4
DOC for Hashimoto
Levothyroxine
Other forms no longer recommended
60mg dessicated thyroid = 100mcg levothyroxine
Levothyroxine dosing Hashimoto, efficacy
1.6 mcg/kg using IBW
Lower if older patient
CV disease: 12.5-25mcg daily
Check again in 4-8 weeks
IV levothyroxine to PO
75% PO dose
Levothyroxine dose subclinical hypothyroid
Elevated TSH, normal T4
25-75mcg
Myxedema Coma therapy
severe, life-threatening hypothyroid
1) 200-400mcg IV levothyroxine followed by 1.6mcg/kg/day
2) Broad spectrum antibiotics
3) Hydrocortisone 100mg q8H
Measure T3 every 1-2 days and adjust levothyroxine dose
Pituitary hormone & secretion inhibitor in Acromegaly
H: Growth hormone
I: Somatostatin or insulin-like growth factor-1
Acromegaly diagnosis
Test: OGTT
Result: Increased insulin-like growth factor-1, increased GH
Would expect increased IGF-1 to suppress GH.
Acromegaly Treatment of Choice
Surgical resection of tumor
Dopamine agonists
Bromocriptine (daily dosing), Cabergoline (weekly dosing)
Acromegaly: bromocriptine
Hyperprolactinemia: cabergoline
Cushing: cabergoline
T2DM: bromocriptine
Ocreotide
Somatostatin analog that blocks GH secretion (endogenous somatostatin is secretion inhibitor for GH)
Used in acromegaly
SC, PO, or LAI
Pegvisomant
GH receptor antagonist that inhibits IGF-1 synthesis in liver (mediator in GH activity)
SC daily
Used in acromegaly
Somatropin
Recombinant GH used for GH deficiency
Pituitary hormones
Growth hormone (GH)
Adrenocorticotropic hormone (ACTH)
Thyroid-stimulating hormone (TSH)
Prolactin
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Adrenal hormones
MIneralocorticoids (aldosterone)
Cortisol
Sex hormones (estradiol, testosterone)
Cushing sydrome
Excessive ACTH secretion results in excessive cortisol secretion due to pituitary adenoma
Cortisol is the primary secretion inhibitor for ACTH. An adenoma prevents this negative feedback loop from working.
Will have normal/elevated plasma ACTH, MRI to confirm
Cushing treatment of choice
Surgical resection of tumor
Pasireotide
MOA: somatostatin analog blocks ACTH secretion
Not effective for adrenally caused Cushing
BID SC inj
Drugs that inhibit Cortisol Synthesis
Osilodrostat
Ketoconazole
Mitotane
Etomidate
Metyrapone
May use in Cushing Syndrome
DOC for hyperaldosteronism
Spironolactone
Alt: eplerenone, amiloride
Addison disease
Primary adrenal insufficiency
Cortisol, aldosterone, androgen deficiencies
Cosyntropin (synthetic ACTH) test diagnoses this
Addison disease treatment
1) Hydrocortisone 15mg/day (or prednisone, cortisone, dexamethasone equiv)
2) Fludrocortisone 0.05-0.2mg/day
3)DHEA 25-50mg IF female & low energy, libido
How to time steroid dose in Addison disease
2/3 in AM, 1/2 in PM
Cortisone 25mg =
Hydrocortisone 20mg
Prednisone 5mg
Prednisolone 5mg
Triamcinolone 4mg
Methylprednisolone 4mg
Dexamethasone 0.75mg
Weight loss therapy goal
5-10% over 6 months
When to start pharmacology tx in obesity
-Obese (BMI >30) after trying lifestyle modifications
-BMI >=27 with significant comorbidities (DM, HTN, dyslipidemia)
Orlistat
MOA: reduces fat absorption by inhibiting gastric/pancreatic lipases
Need multivitamin as reduces absorption of fat-soluble vitamins
Available OTC at reduced dose (60 vs 120mg TID PC)
AE: GI related - fecal urgency, incontinence, oily stools
FDA warning: hepatotoxicity, kidney stones
Phentermine/Topiramate ER
Monitor after 12 weeks: If <3% weight loss, increase dose
Monitor again after 12 weeks: If <5% weight loss, taper slowly off to prevent seizure
Fetal toxicity
Bupropion/Naltrexone ER
Titrate weekly from 1 daily to 2 BID
CI: uncontrolled HTN, seizure, anorexia/bulimia, drug/alcohol withdrawal)
D/C if <5% weight loss after 12 weeks
GLP-1 for weight loss
Liraglutide, Semaglutide
Same starting dose but Higher target doses than diabetes
L: 0.6 > 3mg daily
S: 0.25 > 2.4mg weekly
D/C if <4% weight loss over 16 weeks or cannot tolerate
Tirzepatide - weight loss
GLP1 agonist & GIP agonist
2.5-15mg SC weekly
CV benefit
How does PCOS happen?
Androgen excess
Insulin resistance > Increased insulin secretion > Stimulates androgen secretion > Increases LH with normal or low FSH > Decrease follicular maturation > anovulation
Fertility drugs for PCOS
Clomiphene
Gonadotroptin or Gonadotropin-releasting hormone
Letrozole (DOC*)
Symptom improvement meds for PCOS
Estrogen/progestin hormonal birth control
Metformin
Spironolactone
Pioglitazone (not really recommended)
