Other endocrine drugs

Question 1

Thionamides

Propylthiouracil (PTU), Methimazole

Answer 1

Mech:
Block thyroid peroxidase —> inhibition of thyroid hormone synthesis
Propylthiouracil - blocks 5’-deiodinase –> dec. peripheral conversion of T4 to T3

Use:
Hyperthyroidism

PTU blocks Peripheral conversion and is used in Pregnancy

Adv. effects:
Skin rash
Agranulocytosis
Aplastic anemia
Hepatotoxicity

Methimazole - possible tetratogen - aplasia cutis

Question 2

Levothyroxine (T4)

Triiodothyronine (T3)

Answer 2

Mech:
Thyroid hormone replacement

Use:
Hypothyroidism, myxedema
Used off label as weight loss supplements

Question 3

ADH antagonists

Conivaptan, Tolvaptan

Answer 3

SIADH

Block action at ADH at V2 receptor

Question 4

Desmopressin, acetate

Answer 4

Central DI

Question 5

GH

Answer 5

GH deficiency, Turner syndrome

Question 6

Oxytocin

Answer 6

Stimulates labor
Uterine contractions
Milk let-down
Controls uterine hemorrhage

Question 7

Somatostatin

Answer 7

Acromegaly
Carcinoid syndrome
Gastrinoma
Glucagonoma
Esophageal varices

Question 8

Demeclocycline

Answer 8

Mech: ADH antagonist

Use: SIADH

Adv. effects:
Nephrogenic DI
Photosensitivity
Abnormalities of bone and teeth

Question 9

Glucorticoids

Beclomethasone, Dexamethasone, Hydrocortisone, Methylprednisolone, Prednisone, Triamcinolone

Answer 9

Mech:
Metabolic, catabolic, anti-inflammatory , and immunosuppressive effects mediated by interactions with glucocorticoid response elements, inhibiton of phospholipase A2 and inhibition of transcription factors such as NF-kB

Use:
Adrenal insufficiency 
Inflammation
Immunosuppression
Asthma

Adv. effects:
Iatrogenic Cushing syndrome
Adrenocortical atrophy
Peptic ulcers
Steroid diabetes
Steroid psychosis
Cataracts

Adrenal insufficiency when drug stopped abruptly after chronic use

Question 10

Fludrocortisone

Answer 10

Mech:
Synthetic analog of aldosterone with little glucocorticoid effects

Use:
Mineralocorticoid replacement in primary adrenal insufficiency

Adv. effects:
Similar to glucocorticoids
Edema
Exacerbation of heart failure
Hyperpigmentation

Question 11

Cinacalcet

Answer 11

Mech:
Sensitizes Ca2+ -sensing receptor (CaSR) in parathyroid gland to circulating Ca2+ –> decrease PTH

Use:
Primary or secondary hyperparathyroidism

Adv. effects:
Hypocalcemia