Endocrine Pharmacology Flashcards
What cell type secretes prolactin and where is it secreted from?
Secreted by lactotrophs in anterior pituitary
under what condition is prolactin inhibited?
under high dopamine level
What does hyperprolactinemia lead to?
leads to hypogonadotrophic hypogonadism
What drugs have an effect on dopamine levels and therefore on prolactin ?
Antipsychotics Antiemetics Antidepressants Opiates H2 receptor antagonists
what symptoms may a female with hyperprolactinemia present with?
Amenorrhea (no period – due to hypogonadism from hyperprolactinemia)
Galactorrhea (spontaneous milk flow from breast)
what is the most common functioning pituitary tumour? How can it be identified?
Prolactinoma
Using MRI scan
What is the first line treatment recommended for a prolactinoma? give an example
Dopamine agonists e.g. cabergoline
What is ADH also known as?
Vasopressin
Where is vasopressin/ADH secreted from?
secreted from posterior pituitary
What condition occurs when ADH is no longer secreted?
Cranial Diabetes insipidus
What condition occurs when the body is longer responsive to ADH?
Kidney Diabetes insipidus
what are the 2 types of ADH receptors, where are they found and how dot hey respond to ADH?
V1 receptors: on vascular smooth muscle, cause vasoconstriction
V2 receptors: in DCT and collecting tubule of kidneys, increases the number of aquaporin channels to reabsorb water
What is desmopressin and what effects does it have?
oral form of vasopressin
Has no vasoconstrictor effects so just increases water reabsorption and a has longer half life
What is acromegaly? what causes it?
Hormonal disorder that is caused by pituitary adenoma that leads to excessive growth hormone secretion which stimulates IGF-1
What treatment is there for acromegaly?
Somatostatin analogue
Dopamine agonist
GH receptor antagonist
side effect of somatostatin analogue?
Gallstones
side effect of GH receptor antagonist ?
Liver injury
What treatment is given for hypothyroidism and what from does the thyroxine circulate in?
levothyroxine
Mostly as T4
What are thionamides and how what is their mechanism of action?
Antithyroid drugs
They reduces thyroid hormone synthesis by:
Inhibiting iodide oxidation (to iodine)
Inhibiting iodination of tyrosine (to form MIT/DIT)
Inhibiting coupling of iodotyrosines (to form T3/4)
Name two examples of thionamides, what are their side effects?
Carbimazole - causes low WBC count, concerns about use during pregnancy
Propylthiouracil (PTU) - risk of liver damage
List 3 other treatment options for hyperthyroidism
Beta-blockers – propranolol, reduces sympathetic action, doesn’t affect hormonal levels
Potassium iodide – saturates gland and stops hormones being released
Radioactive iodine
Which diabetes drugs increase insulin levels? give examples
Sulphonylureas e.g. Gliclazide
GLP-1 agonists e.g. Exenatide, liraglutide
DPP-4 inhibitors e.g. Sitagliptin, linagliptin
Insulin
Which diabetes drugs increase insulin sensitivity? give examples
Biguanides e.g. Metformin
Thiazolidinediones e.g. Pioglitazone
Which diabetes drug increases glucose in urine? give examples
SGLT2 inhibitors e.g. Dapagliflozin, canagliflozin
What effect does metformin have?
Reduced hepatic gluconeogenesis
What effect do sulphonylureas have?
Bind to receptor on beta cells, inhibit K+ ATP channels and permit increased insulin secretion
Increased circulating insulin
What is PPARγ? What effect do thiazolidinediones have on it?
PPARγ is a nuclear receptor expressed in adipose tissue, muscle, liver.
They are PPARγ agonists and increase transcription of insulin sensitising genes
What effect doe SGLT2 inhibitors have?
Inhibit SGLT2 transporters which normally reabsorbs glucose in proximal convoluted tubule
Lowers glucose without causing hypoglycaemia
What is the synthetic version of cortisol?
Hydrocortisone
Apart from hydrocortisone, give 3 examples of glucocorticoid preparations
Prednisolone
Dexamethasone
Betamethasone
Aldosterone is a type of ______?
Mineralocorticoid
why can aldosterone not be given orally?
It is metabolised in the liver
Give an example of a synthetic mineralocorticoid
Fludrocortisone
What effect does aldosterone have?
Main action on Na/K pump –> sodium and water reabsorption, loss/excretion of potassium
Give an example of a mineralocorticoid receptor antagonist, what effect does it have?
Spironolactone - block aldosterone receptor
give examples of 2 bisphosphonates used to treat osteoporosis? What effect do they have?
Alendronate
zolendronate
Binds to bone and inhibits osteoclast activity
