Endocrine
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    Diseases

  • Pituitary
    • Overfunction
      • Prolactinoma: females (galactorrhea, amenorrhea), males (gynecomastia, erectile dysfunction), prolactin↑, MRI shows pituitary tumor, tx w bromocriptine, cabergoline.
      • Acromegaly: enlarged body part, sweating, IGF-1↑, GH not suppressed by glucose.
      • Cushing's disease: Cushing's syndrome caused by pituitary tumor (ACTH↑, cortisol suppression by dexamethasone, responds to CRH).
    • Hypopituitarism: deficiency in growth, amenorrhea, thyroid, adrenal insufficiency, pituitary or hypothalamus (respond to RHs) lesion.
      • Craniopharyngioma: visual deficit, headache, hypopituitarism (growth failure, amenorrhea, hypothyroidism), dx w MRI/CT (cystic, calcified, above sella or anywhere along Rathke's), teeth histology.
      • Sheehan's syndrome: difficulty lactating, hypopituitarism, Hx of pregnancy, postpartum hemorrhage/hypotension.
      • Pituitary apoplexy: visual deficit, hypopituitarism (adrenal insuff, hypothyroid), due to sudden hemorrhage near pituitary, dx w MRI/CT.
      • Empty sella syndrome: hypopituitarism (growth retardation in kids) bcz there's no pituitary (MRI).
      • Growth hormone deficiency: growth failure, MSK↓, energy/mood↓, IGF-1↓, insulin-induced hypoglc fail to trigger GH release.
    • Posterior pituitary
      • SIADH: Hyponatremia with natriuresis (urine Na > 40), no edema or dehydration.
      • Diabetes insipidus: thirst, diuresis, due to central (no ADH, alleviated w desmopressin) or nephrogenic (ADH insensitivity), dx serum osmolality↑, urine osmolality↓ even w fluid deprivation, tx w low salt diet, desmopressin (central only).
  • Adrenal
    • Overfunction
      • Aldosteronism: refractory hypertension, hypokalemia, metabolic alkalosis, aldo↓ even w salt loading, tx w eplerenone.
      • Renovascular hypertension: hypertension, abdominal bruits, hypokalemia, dx w angiogram showing renal artery stenosis.
      • Cushing's syndrome: moon face, hirsuitism, buffalo hump, wt gain, striae, hypertension, hyperglycemia, dx w late night saliva & urine cortisol lvls, ddx w ACTH & dexamethasone test.
      • Small cell lung carcinoma: smoker, central mass, biopsy shows small, blue cells, paraneoplastic syndromes (SIADH, ACTH/Cushings).
      • Congenital adrenal hyperplasia: clitoris enlargement in girls, masculinization, early puberty in boys, due to androgen↑ (missing 21-hydroxylase shunts synth toward androgens).
      • Pheochromocytoma: episodic headache, sweating, tachycardia; hypertension, dx w 24 hr urine catecholamine collection, tx w surgery, alpha-blk.
    • Adrenal insufficiency: fatigue, weakness, orthstatic hypotension, hairloss, primary (adrenal gland itself), secondary (pituitary/ACTH), acute (glucocorticoid drug withdrawal), chronic (Addison's).
      • Addison's disease: adrenal insuff: fatigue, weakness, orthostatic hypotension, tanning, due to adrenal gland dz, tx w hydrocortisone, prednisone.
      • Waterhouse-Friderichsen syndrome: N mening sepsis, DIC (plt↓, PT↑, PTT↑), adrenal insuff (cortisol↓), tx w ceftriaxone, hydrocortisone.
  • Thyroid
    • Hyperthyroidism: female, wt loss, heat intolerance, bulging eyes.
      • Graves' disease: female, hyperthyroidism, bulging eyes, goiter, dx w TSH receptor antibodies.
      • Toxic multinodular goiter: female, hyperthyroidism + asymmetric multinodular goiter.
      • Thyroid storm: severe hyperthyroidism = baseline hyperthyroidism + triggering event (surgery, sepsis, iodine, postpartum).
    • Hypothyroidism: female, fatigue, wt gain, cold intolerance, dry skin, brittle nails.
      • Hashimoto's thyroiditis: hypothyroidism, transient hyperthyroidism, goiter, dx w anti-thyroid antibodies, lymphocytic germinal centers.
      • Subacute thyroiditis: hypothyroidism, transient hyperthyroidism, granuloma/giant cells, fibrosis, Hx of URTI.
      • Congenital hypothyroidism: growth failure, jaundice, wt/ht↑, T4↓, TSH↑.
      • Myxedema coma: severe hypothyroidism = baseline hypothyroidism + triggering event (illness, surgery).
      • Drug induced: lithium, amiodarone
    • Tumors
      • Thyroglossal cyst: neck lump (mobile, midline), persistent thyroglossal duct.
      • Follicular adenoma: thyroid adenoma, benign, hyperthyroidism (toxic).
      • Follicular thyroid carcinoma: solitary nodule, biopsy shows malig invasion thru capsule, into blood vessels.
      • Papillary thyroid carcinoma: most common thyroid malig, lymph node mets, papillary architecture, good prog in young women.
      • Medullary thyroid carcinoma: thyroid nodule, calcitonin↑, due to parafollicular C cell malig, biopsy shows amyloid, packets of round cells.
      • Anaplastic thyroid carcinoma: elderly, invasion into trachea, lymph node mets, anaplastic (messy nuclei), very poor prognosis.
  • Parathyroid
    • PTH↑ causing Ca↑
      • Hyperparathyroidism: PTH↑, VitD↑, Ca↑, PO4↓, bone↓.
      • MEN 1: parathyroid, pituitary, pancreas, due to MEN1 (tumor suppr) mut.
      • MEN 2A: medullary, pheo, hyperPTH, due to ret (proto onc).
      • FHH: PTH↑, Ca↑, urine Ca↓.
      • Jaw tumor syndrome: PTH↑ (adenoma), jaw fibroma, due to HRPT2 mut.
      • McCune-Albright syndrome: coast of Maine (cafe-au-lait that respects midline), endocrine excess (PTH↑, precocious), bone mass/fibrosis, due to GNAS mut.
      • Osteitis fibrosa cystica: too much PTH causes bone problems (pain, cyst, fracture).
    • PTH↓ causing Ca↓
      • Hypoparathyroidism: PTH↓, Ca↓, PO4↑.
      • Hypomagnesemia: MSK (weak, cramp), cardio (arrhythmia), endo (PTH↓), Hx of loop, thiazide diuretic, EtOH, malnutrition.
    • Ca↓ causing PTH↑
      • Hypocalcemia: muscle cramp/spasm, numbness and tingling (mouth, hands, feet), bp cuff causes hand spasms, prolonged QT.
      • Vitamin D deficiency: rickets in kids (bones bend), osteomalacia in adults (bones pain, back pain, fractures), 25 Vit D↓, Ca↓, PO4↓.
      • Albright's hereditary osteodystrophy: short stature, round face/obese, short 4th, 5th metacarples, due to PTH insensitivity (Ca↓, PO4↑, PTH&uarr), due to GNAS mut, if paternal inherited then normal biochem (pseudopseudo).
      • Renal failure: edema, proteinuria (foamy), creatinine↑, BUN↑, K↑, bone dz (VitD↓, Ca↓, PTH↑, PO4↑).
    • Ca↑ causing PTH↓
      • Hypercalcemia: renal (polyuria, stones), GI (nausea, constipation), cardio (short QT, valve calcification), MSK (weakness).
      • Vitamin D overdose: Ca↑, 25 Vit D↑, PTH↓.
      • Hypercalcemia of malignancy: Ca↑, due to cancer (PTHrp↑), not due to PTH (PTH↓, 1,25 Vit D↓ or nl) or overdose (25 Vit D↓ or nl).
      • Milk-alkali syndrome: too much Ca intake (antacids, milk) + poor renal fx = Ca↑, alkalosis.
      • Granulomatous & lymphoproliferative diseases
  • Bone diseases
    • Osteitis fibrosa cystica: too much PTH causes bone problems (pain, cyst, fracture).
    • Paget's disease: bone pain, AP↑, due to high bone turnover, pathology shows woven/mosaic bone (instead of lamellar).
    • Vitamin D deficiency: rickets in kids (bones bend), osteomalacia in adults (bones pain, back pain, fractures), 25 Vit D↓, Ca↓, PO4↓.
    • Osteogenesis imperfecta: multiple fractures, blue sclera, hearing loss (otosclerosis), due to collagen dz (type I most common).
    • Osteoporosis: old lady, bone fractures, BMD < 2.5 std dev as measured by DXA.
  • Gonads
    • Hypogonadism: Test/estrogen↓ (decreased sex chars), due to primary/gonadal (LH/FSH↑), or secondary/pituitary (LH/FSH↓), long arms&legs (childhood onset).
      • Primary: dmg to gonads, test/estrogen↓, LH/FSH↑ to compensate
        • Turner's syndrome: XO, neck webbing, short starture, amenorrhea, no barr body.
        • Klinefelter's syndrome: XXY, feminization of males.
        • Hemochromatosis: fatigue, arthralgia, bronze skin, diabetes, LFTs↑, Fe↑ (ferritin, transferrin sat).
      • Secondary: hypothalamus/pituitary, LH/FSH↓ causing test/estrogen↓
        • Kallman's syndrome: anosmia, hypogonadism, due to migration failure of olfatory nerve cells, no GnRH migration to hypothalamus.
        • Hypopituitarism: deficiency in growth, amenorrhea, thyroid, adrenal insufficiency, pituitary or hypothalamus (respond to RHs) lesion.
        • Polycystic ovary syndrome: androgen tumor suppresses LH/FSH, causing infertility, amenorrhea, masculinization.
  • Pancreas
    • Diabetes: thirst, polyuria, hyperglycemia (fasting > 126, OGTT > 200, random > 200) and A1C > 6.5, C peptide (type I = low, type II = high), causes microvascular damage: eyes, nerves, kidneys.
      • Latent autoimmune diabetes: type 1.5: diabetes type 2 progresses to type 1 over time.
      • Ketosis-prone diabetes: type 2 diabetes, African am, hispanic, ketosis, FHx.
      • MODY: monogenic mutation, juvenile onset, mild type 1 diabetes, AD FHx, tx w diet/exercise, sulfonylurea.
      • Gestational diabetes: mild diabetes onset 20 wk of pregnancy, dx w OGTT, resolves after preg, risk for future diabetes development.
      • Cystic fibrosis related diabetes: CF causing prob w insulin secretion.
      • Hyperglycemic hyperosmolar state: stress (MI, infection) triggers glc↑, osmolality↑, dehydration, AMS, type 2 > 1, tx w rehydration, insulin, K.
    • Tumors
      • Insulinoma: hypoglycemia, dx w 72 hr fast: insulin↑, C pep↑, glc↓, tx w diazoxide, octreotide.
      • Glucagonoma: glucagon↑, glc↑, mild diabetes, necro migr erythema.
      • ZES: GERD, PUD, steatorrhea, dx w fasting serum gastrin↑, secretin stimulation causes gastrin↑, tx w PPI, resection, ablation.
      • Somatostatinoma: mild diabetes, gall stones, steatorrhea, Cl↓, somatosatin↑, psammoma.
      • VIPoma: severe diarrhea (secretory), dehydration, dx w elev VIP lvl, CT shows tumor in pancreas, tx w octreotide.
      • MEN 1: parathyroid, pituitary, pancreas, due to MEN1 (tumor suppr) mut.
      • VHL: multisystem tumors: CNS hemangio (neuro), retina angio (vision loss), renal (hematuria), endolymph (hearing loss), AD FHx, dx w VHL mutation.
    • Fasting hypoglycemia
      • Insulin causing hypoglycemia
        • Congenital hyperinsulinism: insulin↑, glc↓, nesidioblastosis (hyper beta cells w dysplasia), mut Kir6, SUR1.
        • Insulinoma: hypoglycemia, dx w 72 hr fast: insulin↑, C pep↑, glc↓, tx w diazoxide, octreotide.
        • Postgastrectomy hypoglycemia: postprandial symptoms due to rapid gastric emptying, incretin↑, insulin↑, tx w small, freq meals, acarbose.
        • Drugs: insulin, sulfonylurea
      • Hypoglycemia causing low insulin
        • von Gierke's disease (type 1): hepatomegaly (glycogen), severe fasting hypoglycemia, lactic acidosis, due to defect glc-6-phosphatase.
        • Growth hormone deficiency: growth failure, MSK↓, energy/mood↓, IGF-1↓, insulin-induced hypoglc fail to trigger GH release.
        • Adrenal insufficiency: fatigue, weakness, orthstatic hypotension, hairloss, primary (adrenal gland itself), secondary (pituitary/ACTH), acute (glucocorticoid drug withdrawal), chronic (Addison's).
        • Drugs: EtOH, quinine, salicylate, pentamidine
  • Other
    • Primary polydipsia: polydipsia, both serum and urine osmolality↓, fluid deprivation will concentrate urine.
    • Central pontine myelinolysis: dysarthria, ataxia, quadriplegia, seizures, Hx of hyponatremia tx, risk factors = malnutrition, hypokalemia, liver dz.
    • MEN 2B: medullary, pheo, marfan, mucosal neuroma, due to ret.
    • Pseudohypercalcemia: serum Ca↑ bcz albumin↑.
    • Pseudohypocalcemia: Ca↓ bcz albumin↓.
    • Idiopathic postprandial syndrome: postprandial symptoms, sugar normal, sensitivity to post-meal autonomic responses.

    • Drugs

  • Pituitary
    • Agonist
      • Thypinone: Tx: ddx hypo/hyperthyroidism (hypo will respond w TSH). Mech: TRH.
      • Corticorelin: Tx: ddx Cushings (if pituitary, then ACTH will respond). Mech: CRH.
      • Gonadorelin: Tx: induce ovulation, spermatogenesis. Mech: GnRH.
      • hGH: Tx: growth hormone deficiency.
      • Desmopressin (DDAVP,): Tx: central DI, VWD. Mech: V2 selective (antidiuretic).
    • Antagonist
      • Leuprolide: Tx: precocity, endometriosis, uterine fibroids, breast, prostate cancer. Mech: LH/FSH antag (neg feedback, bind pituitary GnRH receptor).
      • Octreotide: Tx: acromegaly, VIPoma, insulinoma, carcinoid syndrome. Mech: somatostatin analogue, inh growth hormone, glucagon, insulin.
      • Bromocriptine: Tx: Parkinson, prolactinoma. Mech: dopamine agonist. SE: hallucination.
      • Cabergoline: Tx: prolactinoma. Mech: dopamine agonist (inh prolactin).
      • Pegvisomant: Tx: acromegaly. Mech: GH receptor antag. SE: hepatitis.
      • Tolvaptan: Tx: SIADH, hyponatremia. Mech: V2 antag.
  • Adrenal
    • Agonist
      • Hydrocortisone: Tx: adrenal insufficiency. Mech: gluco = mineralo.
      • Fludrocortisone: Tx: primary adrenal insufficiency. Mech: mineralocorticoid >> gluco.
    • Antagonist
      • Ketoconazole: Tx: antifungal, antiandrogen. Mech: inh lanosterol→ergosterol, inh androgen synth.
      • Aminoglutethimide: Tx: Cushing's. Mech: anti-steroid (aromatase, cholesterol→pregnenolone).
      • Mifepristone: Tx: Cushing's. Mech: glucocorticoid receptor antag.
      • Mitotane: Tx: adrenocortical carcinoma. Mech: adrenocortical mitochondria destruction.
      • Dexamethasone: Tx: dexameth suppr test. Mech: glucocorticoid >> mineralo, suppress pituitary ACTH.
      • Eplerenone: Tx: K sparing diuretic, aldosteronism. Mech: aldosterone antag, compete w mineralocorticoid receptor. SE: hyperkalemia.
      • Spirinolactone: Tx: K sparing diuretic, aldosteronism, anti-androgen. Mech: compete w aldosterone receptor.
  • Thyroid
    • Agonist
      • Levothyroxine: Tx: hypothyroidism. Mech: synthetic T4.
      • Thyrogen: Tx: monitor thyroid cancer. Mech: synthetic TSH, stimulates cancer to make Tg.
    • Antagonist
      • Methimazole: Tx: hyperthyroidism. Mech: inh thyroid peroxidase (iodination of Tg). SE: agranulocytosis.
      • Propylthiouracil (PTU,): Tx: hypothyroidism. Mech: inh thyroperoxidase (iodination Tg), 5'-deiodinase (T4→T3). SE: hepatotox, agranulocytosis. Fact: preferred for 1st trimester of preg.
      • Radioactive iodine: Tx: hyperthyroidism. SE: hypothyroidism.
      • SSKI: Tx: hyperthyroidism. Mech: iodide suppress T4 secretion.
  • Parathyroid
    • Cinacalcet: Tx: hyperPTH. Mech: calcimimetic neg feedback on Ca receptor.
  • Bone agonist
    • Bisphosphonate (Diphosphate,): Tx: osteoporosis. Mech: sticks to bones, poisons osteoclasts. Fact: the -dronates.
      • Alendronate: Tx: osteoporosis. Mech: bisphosphonate. Fact: weekly oral.
      • Risedronate: Tx: osteoporosis. Mech: bisphosphonate. Fact: monthly oral.
      • Ibandronate: Tx: osteoporosis. Mech: bisphosphonate. Fact: monthly oral, no hip protection.
      • Zoledronate: Tx: osteoporosis. Mech: bisphosphonate. Fact: yearly IV.
    • Osteoprotegerin: Tx: osteoporosis. Mech: decoy receptor for RANKL (which is osteoclast agonist).
    • Denosumab: Tx: osteoporosis. Mech: anti-RANKL.
    • Teriparatide: Tx: osteoporosis. Mech: PTH analogue, stim osteoblast > clast. SE: osteosarcoma, too much of it will stim osteoclasts. Fact: use only intermittently to avoid stim osteoclasts.
    • Raloxifene: Tx: osteoporosis. Mech: SERM: proestrogen on bone, antiestrogen on breast. SE: clots.
    • Calcitonin: Tx: osteoporosis.
  • Pancreas
    • Misc
      • Fructosamine: Tx: the A1C equivalent for pt w abnormal RBC turnover. Mech: glycated albumin.
    • Anti-insulin: tx insulinoma
      • Diazoxide: Tx: insulinoma. Mech: inh insulin secretion (open ATP sensitive K channels in beta cells). SE: edema, hirsuit, GI.
      • Octreotide: Tx: acromegaly, VIPoma, insulinoma, carcinoid syndrome. Mech: somatostatin analogue, inh growth hormone, glucagon, insulin.
      • Streptozotocin: Tx: insulinoma. Mech: beta cell tox.
    • Pro-insulin: tx diabetes
      • Sulfonylurea: Tx: type 2 diabetes. Mech: inc insulin release. SE: hypoglycemia, teratogenic, wt gain.
        • Tolbutamide: Tx: type 2 diabetes. Mech: sulfonylurea. SE: wt gain, hypoglycemia. Fact: short duration (tid).
        • Chlorpropamide: Tx: type 2 diabetes. Mech: sulfonylurea (insulin↑). SE: wt gain, hypoglycemia. Fact: long duration (qd).
        • Glipizide: Tx: type 2 diabetes. Mech: sulfonylurea. SE: wt gain, hypoglycemia.
        • Glyburide (Glibendamide,): Tx: type 2 diabetes. Mech: sulfonylurea. SE: wt gain, hypoglycemia.
        • Glimepiride: Tx: type 2 diabetes. Mech: sulfonylurea. SE: wt gain, hypoglycemia. Fact: long duration (qd).
      • Meglitinide: Tx: type 2 diabetes. Mech: inc insulin secretion. SE: wt gain, hypoglycemia. Fact: the -glinides.
        • Repaglinide: Tx: type 2 diabetes. Mech: meglitinide (inc insulin). SE: wt gain, hypoglycemia.
        • Nateglinide: Tx: type 2 diabetes. Mech: meglitinide (inc insulin). SE: wt gain, hypoglycemia.
      • Glitazone (Thiazolidinedione,): Tx: type 2 diabetes. Mech: activate PPARγ (FFA recept), inc muscle/fat insulin sensitivity, adipokine↑, GLUT↑. SE: edema, wt gain, CHF, heptox, fractures. Fact: slow onset.
        • Pioglitazone: Tx: type 2 diabetes. Mech: glitazone. SE: edema, wt gain, CHF, heptox, fractures. Fact: lower lipids.
        • Rosiglitazone: Tx: type 2 diabetes. Mech: glitazone. SE: edema, wt gain, CHF, heptox, fractures. Fact: inc LDL.
      • Alpha-glucosidase inhibitor: Tx: type 2 diabetes, postprandial hyperglycemia. Mech: delay CHO gut absorption. SE: gas, LFTs. Fact: acarbose, miglitol.
        • Acarbose: Tx: type 2 diabetes, postprandial hyperglycemia. Mech: alpha glucosidase inh. SE: gas, LFTs.
        • Miglitol: Tx: type 2 diabetes, postprandial hyperglycemia. Mech: alpha glucosidase inh. SE: gas, LFTs.
      • GLP-1 analogue: Tx: type 2 diabetes. Mech: incretin agonist, glucagon↓, insulin↑, slow gastric emptying, satiety, wt loss. Fact: GLP = glucagon-like-peptide.
        • Exenatide: Tx: type 2 diabetes. Mech: GLP1 analogue.
        • Liraglutide: Tx: type 2 diabetes. Mech: GLP1 analogue.
      • DPP-IV inhibitor (Glipitin,): Tx: type 2 diabetes. Mech: incretin↑ (inh breakdown by DPP4). Fact: the -liptins.
        • Sitagliptin: Tx: type 2 diabetes. Mech: DPP4 inh.
        • Saxagliptin: Tx: type 2 diabetes. Mech: DPP4 inh.
        • Linagliptin: Tx: type 2 diabetes. Mech: DPP4 inh.
      • Metformin (Biguanide,): Tx: type 2 diabetes (first line), lower lipids & wt. Mech: inc liver insulin sensitivity, AMPK, gluconeo↓. SE: GI, B12↓, lactic acidosis, contraindicated in hep, cardio, renal dz or IV contrast.
      • Pramlintide: Tx: diabetes. Mech: amylin↑ (satiety, glucagon↓, slow gastric emptying). Fact: wt loss.
      • Colesevelam: Tx: hyperlipidemia in type 2 diabetes. Mech: bile acid sequestrant. SE: GI, TG↑.
      • Bromocriptine: Tx: Parkinson, prolactinoma. Mech: dopamine agonist. SE: hallucination.
      • Human insulin
        • Regular insulin: Tx: diabetes. Fact: human, short acting.
        • NPH: Tx: diabetes. Mech: human insulin xtals in protamine. Fact: intermediate acting.
      • Rapid acting insulin analogue
        • Aspart: Tx: diabetes, postprandial hyperglycemia. Mech: monomeric. SE: spike hypoglycemia. Fact: rapid acting insulin analogue.
        • Glulisine: Tx: diabetes. Mech: monomeric. SE: spike hypoglycemia. Fact: rapid acting insulin analogue.
        • Lispro: Tx: diabetes. Mech: monomeric. SE: spike hypoglycemia. Fact: rapid acting insulin analogue.
      • Long acting insulin analogue
        • Glargine: Tx: diabetes. Mech: acid soluble, body pH insoluble (last longer). Fact: steady, long acting.
        • Detemir: Tx: diabetes. Mech: FA sidechain, self assoc hexamer, assoc w albumin. Fact: intermediate-long acting.
  • Obesity tx
    • Dexamphetamine: Tx: ADHD, narcolepsy, obesity. Mech: stimulant, inc release of NE, DA.
    • Phentermine (Adipex,): Tx: obesity. Mech: stimulant, inc release of NE, DA (early satiety). SE: hypertension.
    • Fenfluramine: Tx: obesity. Mech: 5-HT release.
    • Dexfenfluramine: Tx: obesity. Mech: 5-HT release.
    • Orlistat: Tx: obesity. Mech: inh pancreatic lipase. SE: GI (tx w metamucil), malabsorption (tx w multi vit). Fact: lower lipids and blood sugar.