Endocrine Pharmacology Flashcards
List the 3 types of hormones found and their recepotrs
- Peptide hormone - cell surface receptor
- Steroid hormone - intracellular receptor
- Thyroid hormone - nuclear receptor
List the organs of the endocrine system
Hypothalamus Pituitary Thyroid Parathyroid Pancreas Adrenal glands Gonads
List the main routes of drug administration
Oral Sublingual Topical Inhalation Injection - subcutaneous - IM - IV - IT - intravitreal
List the different types of injection administration
Injection
- subcutaneous
- IM
- IV
- IT
- intravitreal
Define pharmacokinetics
What the body does to the drug
- Absorption - rate and bioavailability
- Distribution
- Metabolism - first pass (GI/Liver)
- Excretion - hepatic/renal
Define pharmacodynamics
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
What is prolactinoma?
Benign pituitary adenoma
What are the functions of prolactin?
- Stimulates lactation
Where is prolactin secreted from?
Lactotrophs in the adenohypophysis
How is prolactin regulated?
Under tonic inhibition by dopamine secreted from the hypothalamus
What is the consequence of a prolactinoma?
Hyperprolactinuemia (excess prolactin
Leads to hypogonadotrophic hypogonadism
- GnRH Deficiency
- Decreased levels of FSH and LH
What drugs affect prolactin?
Any drug that interfers with dopamine action can cause hyperprolactinaemia (any drug that decreases dopamine) - Anti-psychotics - anti-emetics - anti-depressants - opoates - H2R antagonist
How would you Dx prolactinoma?
MRI
How would you Tx prolactinoma?
- Medical
- dopamine (D2) agonist
- carbergoline
What type of hormone is vasopressin? And where is it secreted from?
Peptide hormone secreted from neurohypophysis
What triggers the release of vasopressin?
ADH is released in response to
- low plasma volume
- increased serum osmolality
Where does vasopressin act on?
distal part of nephron and collecting tubules
via V2R receptors which translocate aquaporin channels to reabsorb water
What condition is caused when there is a lack of or resistance to vassopressin?
Diabetes insipidus
What effect does vasopressing have on the VSMCs?
Vasoconstriction
How would you treat cranial diabetes insipidus? Name a drug
Give synthetic analogue of ADH with no vasoconstrictor effects
- ddAVP
- Desmopressin
What is the MOA cascade of TSH?
TSH acts on receptors on the membrane of thyroid follicles trough cAMP-PI3K cascade
What effect does increase iodide plasma have on the thyroid?
Size and vascularity reduced
How would you Tx hypothyroidism?
Name some drugs
Thyroid hormone replacement therapy
- Synthetic T4 (levothyroxine)
- Synthetic T3 (liothyronine)
Tx hyperthyroidism MAIN TX
Name some drugs
Anti-thyroid drugs
-Thionamides (orally)
- Carbimazole (1st line)
- absorbed well from the gut and converted into methimazole via 1st passag metabolism - Propylthiouracil (PTU)
- less active
What is the mechanism of action of hyperthyroid drugs?
Anti-thyroid drugs
- inhibit iodine oxidation (thyroperoxidase)
- inhibit iodination of tyrosine
- inhibit coupling of iodothyrosines (DIT MIT)
- takes weeks to reduce circulating hormones
What diseases are included in matabolic syndrome?
Diabetes
Obesity
Hypertension
Dyslipidaemia
Which is more effective IV or oral glucose? Why?
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)
Tx T2DM
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
What are the main mechanisms of T2DM drugs?
- Increase insulin secretion
- Sulphonulreas - e.g. glicazide
- GLP-1 agonist - e.g. exantide
- DPP-4 antagonists - e.g. liagliptin
- Exogenous insulin - Increase peripheral insulin sensititivty
- biguanides - metformin
- thiozolidinediones - piolitazone - Decrease glucose reabsorption
- SGLT2 inhibitors - cana- , dapa, empagliflozin
Where does insulin act?
Receptor tyrosine kinase on target cells
What are the main insulin preperations?
- short acting
- intermediate/long-acting (precipitated with zinc)
- slow absorption - premixed
What are the different delivery methods for insulin?
Subcutaneous injection
Continuous subcutaneous insulin infusion (defive
IV (acutely)
IM
How would you Tx emergency hyperkalaemia?
Give IV insulin
what is the most common preparation of corisol?
Hydrocorisone
Where is aldosterone metabolised?
Liver
Therefore cannot be given orally
What drug is use to treat Addison’s disease?
Fludrocortisone
Orally
What are bisphophonates?
Drugs used to Tx osteoporosis
How do bisphosphonates work?
Reduce bone resorption
Bind to bone and inhibit osteoclastic activity
