Endocrine Pharmacology

Question 1

List the 3 types of hormones found and their recepotrs

Answer 1

1. Peptide hormone - cell surface receptor
2. Steroid hormone - intracellular receptor
3. Thyroid hormone - nuclear receptor

Question 2

List the organs of the endocrine system

Answer 2

Hypothalamus
Pituitary
Thyroid
Parathyroid
Pancreas
Adrenal glands
Gonads

Question 3

List the main routes of drug administration

Answer 3

Oral
Sublingual 
Topical
Inhalation
Injection
- subcutaneous
- IM
- IV
- IT
- intravitreal

Question 4

List the different types of injection administration

Answer 4

Injection

• subcutaneous
• IM
• IV
• IT
• intravitreal

Question 5

Define pharmacokinetics

Answer 5

What the body does to the drug

• Absorption - rate and bioavailability
• Distribution
• Metabolism - first pass (GI/Liver)
• Excretion - hepatic/renal

Question 6

Define pharmacodynamics

Answer 6

What the drug does to the body

• Receptor binding - Agonist/antagonist/partial agonist
• Action on ion channels - blockers/mediators
• Action in enzymes - blockers/false substrate/ produrg
• Transporters
• Cytotoxic agents

Question 7

What is prolactinoma?

Answer 7

Benign pituitary adenoma

Question 8

What are the functions of prolactin?

Answer 8

• Stimulates lactation

Question 9

Where is prolactin secreted from?

Answer 9

Lactotrophs in the adenohypophysis

Question 10

How is prolactin regulated?

Answer 10

Under tonic inhibition by dopamine secreted from the hypothalamus

Question 11

What is the consequence of a prolactinoma?

Answer 11

Hyperprolactinuemia (excess prolactin

Leads to hypogonadotrophic hypogonadism

• GnRH Deficiency
• Decreased levels of FSH and LH

Question 12

What drugs affect prolactin?

Answer 12

Any drug that interfers with dopamine action can cause hyperprolactinaemia 
(any drug that decreases dopamine)
- Anti-psychotics
- anti-emetics
- anti-depressants
- opoates
- H2R antagonist

Question 13

How would you Dx prolactinoma?

Answer 13

MRI

Question 14

How would you Tx prolactinoma?

Answer 14

1. Medical
   - dopamine (D2) agonist
   - carbergoline

Question 15

What type of hormone is vasopressin? And where is it secreted from?

Answer 15

Peptide hormone secreted from neurohypophysis

Question 16

What triggers the release of vasopressin?

Answer 16

ADH is released in response to

• low plasma volume
• increased serum osmolality

Question 17

Where does vasopressin act on?

Answer 17

distal part of nephron and collecting tubules

via V2R receptors which translocate aquaporin channels to reabsorb water

Question 18

What condition is caused when there is a lack of or resistance to vassopressin?

Answer 18

Diabetes insipidus

Question 19

What effect does vasopressing have on the VSMCs?

Answer 19

Vasoconstriction

Question 20

How would you treat cranial diabetes insipidus? Name a drug

Answer 20

Give synthetic analogue of ADH with no vasoconstrictor effects

• ddAVP
• Desmopressin

Question 21

What is the MOA cascade of TSH?

Answer 21

TSH acts on receptors on the membrane of thyroid follicles trough cAMP-PI3K cascade

Question 22

What effect does increase iodide plasma have on the thyroid?

Answer 22

Size and vascularity reduced

Question 23

How would you Tx hypothyroidism?

Name some drugs

Answer 23

Thyroid hormone replacement therapy

• Synthetic T4 (levothyroxine)
• Synthetic T3 (liothyronine)

Question 24

Tx hyperthyroidism MAIN TX

Name some drugs

Answer 24

Anti-thyroid drugs
-Thionamides (orally)

1. Carbimazole (1st line)
   - absorbed well from the gut and converted into methimazole via 1st passag metabolism
2. Propylthiouracil (PTU)
   - less active

Question 25

What is the mechanism of action of hyperthyroid drugs?

Answer 25

Anti-thyroid drugs

• inhibit iodine oxidation (thyroperoxidase)
• inhibit iodination of tyrosine
• inhibit coupling of iodothyrosines (DIT MIT)
• takes weeks to reduce circulating hormones

Question 26

What diseases are included in matabolic syndrome?

Answer 26

Diabetes
Obesity
Hypertension
Dyslipidaemia

Question 27

Which is more effective IV or oral glucose? Why?

Answer 27

Oral glucose is more effecting at stimulating insulin secretion than IV glucose because of the action of gut incretin hormones which promote insulin secretion (GLP and GIP)

Question 28

Tx T2DM

Answer 28

1st line: metformin (or sulphonyurea if intolerant)

2nd line: sulphonylurea (or pioglitazone - TZD)

3rd line:

• oral: pioglitizone and/or DPP inhibitor
• inject: insulin and/or GLP1 agonist

Question 29

What are the main mechanisms of T2DM drugs?

Answer 29

1. Increase insulin secretion
   - Sulphonulreas - e.g. glicazide
   - GLP-1 agonist - e.g. exantide
   - DPP-4 antagonists - e.g. liagliptin
   - Exogenous insulin
2. Increase peripheral insulin sensititivty
   - biguanides - metformin
   - thiozolidinediones - piolitazone
3. Decrease glucose reabsorption
   - SGLT2 inhibitors - cana- , dapa, empagliflozin

Question 30

Where does insulin act?

Answer 30

Receptor tyrosine kinase on target cells

Question 31

What are the main insulin preperations?

Answer 31

1. short acting
2. intermediate/long-acting (precipitated with zinc)
   - slow absorption
3. premixed

Question 32

What are the different delivery methods for insulin?

Answer 32

Subcutaneous injection
Continuous subcutaneous insulin infusion (defive
IV (acutely)
IM

Question 33

How would you Tx emergency hyperkalaemia?

Answer 33

Give IV insulin

Question 34

what is the most common preparation of corisol?

Answer 34

Hydrocorisone

Question 35

Where is aldosterone metabolised?

Answer 35

Liver

Therefore cannot be given orally

Question 36

What drug is use to treat Addison’s disease?

Answer 36

Fludrocortisone

Orally

Question 37

What are bisphophonates?

Answer 37

Drugs used to Tx osteoporosis

Question 38

How do bisphosphonates work?

Answer 38

Reduce bone resorption

Bind to bone and inhibit osteoclastic activity