endo exam 3 drug classes n mechanisms

Somatropin class?

Recombinant growth hormone

Octreotide class?

Somatostatin analog

Octreotide effect in acromegaly?

Reduces GH release

Pegvisomant class?

GH receptor antagonist

Pegvisomant effect on IGF-1?

Decreases IGF-1; doesn't treat tumor directly

Cabergoline class?

Dopamine D2 agonist

Bromocriptine class?

Dopamine D2 agonist

D2 agonists effect on prolactin?

Decrease prolactin

D2 blockers effect on prolactin?

Increase prolactin

Methimazole drug class?

Thioamide antithyroid agent

Methimazole mechanism?

Blocks TPO; reduces new T3/T4 synthesis

PTU drug class?

Thioamide antithyroid agent

PTU mechanism beyond TPO inhibition?

Blocks peripheral T4→T3 conversion

Preferred thioamide in most cases?

Methimazole

Preferred thioamide in first trimester?

PTU

Preferred thioamide during thyroid storm?

PTU in the provided lecture

Methimazole dose schedule vs PTU?

Typically daily vs PTU 2–3 times/day

Propranolol role in hyperthyroidism?

Relieves adrenergic symptoms; may reduce T4→T3

Beta blocker contraindicated in thyrotoxicosis: rate agents?

Diltiazem or verapamil

Iodide acute effect on thyroid?

Temporarily suppresses hormone synthesis/release

Radioactive iodine (I-131) mechanism?

Destroys thyroid follicular cells

Levothyroxine class?

Synthetic T4 replacement

Liothyronine class?

Synthetic T3 replacement

Desmopressin class?

Selective V2 receptor agonist

Desmopressin principal indication in notes?

Central DI

Tolvaptan class?

V2 receptor antagonist

Tolvaptan kidney effect?

Increases free-water excretion

Demeclocycline SIADH mechanism?

Reduces renal action of ADH

Why do thiazides help nephrogenic DI?

Paradoxically reduce urine volume via increased proximal reabsorption

Common drug causing nephrogenic DI?

Lithium

Common antidepressant class associated with SIADH?

SSRIs

Combination oral contraceptives contain?

Estrogen plus progestin

COC mechanism of pregnancy prevention?

Suppress FSH/ovulation LH surge; progestin thickens mucus

Norethindrone mini-pill class?

Progestin-only oral contraceptive

Traditional mini-pill important mechanism?

Thick cervical mucus; ovulation suppression inconsistent

Spironolactone class?

Antiandrogen and potassium-sparing diuretic

Spironolactone in feminizing therapy?

Reduces androgen effects

Testosterone in masculinizing therapy?

Androgen replacement; can be monotherapy

Flutamide drug class?

Nonsteroidal androgen receptor antagonist

Bicalutamide drug class?

Nonsteroidal androgen receptor antagonist

Finasteride drug class?

5α-reductase inhibitor

Finasteride isoform selectivity?

Inhibits type 2 5α-reductase

Dutasteride drug class?

5α-reductase inhibitor

Dutasteride isoform selectivity?

Inhibits types 1 and 2 5α-reductase

What do -steride drugs lower?

DHT by blocking testosterone conversion

Leuprolide class?

GnRH agonist

Goserelin class?

GnRH agonist

Nafarelin class?

GnRH agonist

Why do continuous GnRH agonists lower T?

Receptor downregulation → less LH/FSH → less testosterone

Megestrol acetate drug class?

Progestin

Cyproterone acetate drug class?

Steroidal antiandrogen/androgen receptor antagonist

Hydrocortisone drug class?

Glucocorticoid (cortisol replacement)

Prednisone and dexamethasone class?

Glucocorticoids

Effect of external glucocorticoids on HPA axis?

Negative feedback suppresses ACTH and adrenal cortisol output