pituitary related drugs

Question 1

hormone release from pituitary

Answer 1

posterior: hormones produced in hypothalamus and stored in post pit (oxytocin and ADH - vasopressin)

anterior: hormones produced in ant pit but stimulated by releasing factors from hypothalamus (GH, ACTH,TSH, FSH, LH, prolactin

Question 2

use of pituitry related drugs

Answer 2

• replacement therapy in hormone deficiency
• therapy to produce a specific response when a hormone excess is present

Question 3

anterior pituitary agents

Answer 3

• somatropin (GH)
• octreotide

Question 4

posterior pituitary agents

Answer 4

• vasopressin/desmopressin

Question 5

control of GH release

Answer 5

GH from ant pitm controlled by GH-RH (stimulate release) and somatostatin (inhibit release)

Question 6

GH deficiency what does it do and treatment

Answer 6

• pediatric short stature (less IFG-1 which helps growth)
• adult muscle mass loss
• somatropin: recombinant GH (purified peptide), SC injection daily
• pediatric: stimulate skeletal growth (before growth plates close)
• adults: increase lean muscle mass, decrease adipose mass

Question 7

GH excess

Answer 7

gigantism:
- GH excess in childhood (7-9 feet tall)
- pituitary tumour (surgical removal)
- body proportions normal
- headache, profuse sweating, soft tissue swelling, cardiomegaly, HTN, joint pain, diabetes

acromegaly:
- GH excess in adulthood
- coarse facial features, large hands, feet
- headache, profuse sweating, soft tissue, swelling, cardiomegaly, HTN, joint pain, diabetes
- treatment: surgery, radiation, drugs

Question 8

GH excess drugs

Answer 8

octreotide, lanreotide, pasireotide
- mimics somatostatin
- inhibits GH release
- SC or IM
- peptide
- daily or depot

Question 9

diabetes insipidus (low vasopressin amount)

Answer 9

• production of large volume of dilute urine: deficiency of vasopressin/ADH
• vasopressin increases water reabsorption from collecting ducts
• decreased vasopressin can lead to 25L excreted/day

Question 10

central diabetes insipidus

Answer 10

most common
- brain surgery and head trauma are common causes
- severity depends on how much vasopressin is released
- condition may be transient or persistent

Question 11

diabetes insipidus treatment

Answer 11

• vasopressin
• desmopressin (used for bedwetting, nocturnal enuresis)
  to reduce urinary output and severe thirst

desmopressin preferred:
- given PO or intranasal
- longer duration of action
- better adverse effect profile
- no vasoconstrictor activity

Question 12

vasopressin/desmopressin adverse effects

Answer 12

water intoxication
- drowsiness, headache, lightheadedness, SOB
- hyponatremia

Question 13

other uses of desmopressin

Answer 13

clotting disorders
- hemophilia A
- von willebrand’s disease
- increase clotting factor 8