CH 62 Drugs Related to Hypothalamic & Pituitary Function

Question 1

Drug: Octreotide (Sandostatin)

Answer 1

Class: Somatostatin analogs
MOA: Mimic somatostatin to inhibit growth hormone (GH) release from the anterior pituitary.
Note: Used to treat acromegaly

Question 2

Drug: Lanreotide (Somatuline)

Answer 2

Class: Somatostatin analogs
MOA: Mimic somatostatin to inhibit growth hormone (GH) release from the anterior pituitary.
Note: Used to treat acromegaly; lanreotide may reduce fertility in women.

Question 3

Drug: Cabergoline (Dostinex)

Answer 3

Class: Dopamine agonist
MOA: Activates dopamine receptors in the anterior pituitary to suppress prolactin secretion.
Note: Can be discontinued after 6 months of normalized prolactin levels.

Question 4

Drug: Bromocriptine (Parlodel)

Answer 4

Class: Dopamine agonist
MOA: Activates dopamine receptors in the anterior pituitary to suppress prolactin secretion.
Note: Also used to treat Parkinson’s disease and type 2 diabetes.

Question 5

Drug: Desmopressin (DDAVP, Nocdurna, Noctiva, Stimate)

Answer 5

Class: Synthetic antidiuretic hormone (ADH)
MOA: Enhances water reabsorption in renal collecting ducts by activating V2 receptors.
Note: Used for enuresis (bed-wetting); fluid intake must be carefully managed.

Question 6

Drug: Vasopressin (Pitressin)

Answer 6

Class: Endogenous antidiuretic hormone
MOA: Promotes renal water reabsorption by acting on V2 receptors; also has vasoconstrictive V1 receptor activity.
Note: Natural form of ADH; desmopressin is a synthetic analog with fewer vasoconstrictive effects.

Question 7

Drug: Leuprolide (Lupron)

Answer 7

Class: GnRH analog
MOA: Suppresses LH and FSH secretion after initial stimulation by continuously activating GnRH receptors.
Note: Used for prostate cancer, endometriosis, and gender-affirming therapy.

Question 8

Drug: Goserelin (Zoladex)

Answer 8

Class: GnRH analog
MOA: Suppresses LH and FSH secretion after initial stimulation by continuously activating GnRH receptors.
Note: Used for prostate cancer, endometriosis, and gender-affirming therapy.

Question 9

Drug: Somatostatin (Somatostatin UCB, Stilamin, Somastat)

Answer 9

Class: Growth hormone-inhibiting hormone
MOA: Inhibits GH release from the anterior pituitary; also inhibits insulin and GI hormones.
Note: Naturally produced in the brain and gut; slows hormone secretion systemically.

Question 10

Hormones produced/released by the anterior pituitary

Answer 10

• ACTH (adrenocorticotropic hormone)
• TSH (thyroid-stimulating hormone)
• GH (growth hormone)
• PRL (prolactin)
• FSH (follicle-stimulating hormone)
• LH (luteinizing hormone)

Question 11

Hormones produced in hypothalamus & released by posterior pituitary

Answer 11

• ADH (antidiuretic hormone)
• Oxytocin

Question 12

Releasing hormones produced by hypothalamus

Answer 12

• TRH (thyrotropin-releasing hormone)
• CRH (corticotropin-releasing hormone)
• GnRH (gonadotropin-releasing hormone)
• GHRH (growth hormone-releasing hormone)
• Somatostatin (inhibits GH & TSH)
• Dopamine (inhibits prolactin)

Question 13

Function of growth hormone (GH)

Answer 13

• Stimulates growth (bone & muscle)
• Increases protein synthesis
• Promotes fat breakdown
• Increases blood glucose (anti-insulin effect)

Question 14

Conditions linked to GH excess/deficiency + treatment

Answer 14

Excess:
* Children: Gigantism
* Adults: Acromegaly
* Treatment: Surgery, radiation, somatostatin analogs (e.g., octreotide)

Deficiency:
* Children: Dwarfism
* Adults: Fatigue, low muscle mass
* Treatment: GH replacement (somatropin)

Question 15

Adverse effects of GH therapy

Answer 15

• Edema
• Joint/muscle pain
• Hyperglycemia
• Intracranial hypertension
• Risk of neoplasia (rare)

Question 16

Function of prolactin (PRL), effects of excess, & tx

Answer 16

Function: Stimulates breast development & milk production

Excess PRL:
* Women: Amenorrhea, galactorrhea, infertility
* Men: Decreased libido, gynecomastia

Treatment: Dopamine agonists (e.g., bromocriptine, cabergoline)

Question 17

Therapeutic uses for antidiuretic hormone (ADH)

Answer 17

• Diabetes insipidus (central type) - decreases urine output
• Nocturnal enuresis - DDAVP (synthetic ADH) at bedtime
• Shock/hypotension (vasopressin use in ICU)
• post-op abdominal distention - reduces gas
• pre-op abdominal radiography - clears gas shadows
• Hemophilia A - promotes production of Factor VIII
• Von Willebrand disease - promotes production of Factor VIII

Question 18

Physiologic effects of oxytocin

Answer 18

1. Stimulates uterine contractions during labor
2. Promotes milk ejection during breastfeeding