Endocrinology

Question 1

What drug can be used in the management of SIADH? What is its mechanism?

Answer 1

Demeclocycline (decreases the responsiveness of collecting tubules to ADH)

Question 2

How do loop diuretics work?

Answer 2

inhibit NKCC2 co-transporter in ascending loop of Henle

Question 3

commonest cause of Conn’s syndrome? Second commonest?

Answer 3

Bilateral adrenal hyperplasia

second: adrenal adenoma

Question 4

How does aldosterone work?

Answer 4

Hypokalaemia

increases Na/H20 abdorption kidney –> hypertension

Question 5

Commonest cause of primary hyperparathyroidism?

Answer 5

Single parathyroid adenoma

Question 6

Explain the management of conn’s?

Answer 6

Depends on the cause

If bilateral adrenal hyperplasia - use aldosterone antagonist (spironolactone)

If adrenal adenoma –> adrenelectomy

Question 7

What is barttle’s syndrome and how do you remember it?

Answer 7

A.R. condition affecting the NKCC2 co-transporter in the ascending loop of henle

Causes hypokalaemia, polyuria, polydipsia etc

It is like giving loads of furosemide which blocks the same co-transporter

Question 8

What does a normal short synacthen test not exclude when assessing for adrenocortical insufficiency?

Answer 8

Pituitary failure

Question 9

What metabolic derangements

Answer 9

Hyperkalaemia
Hyponatraemia
Hypoglycaemia
Metabolic acidosis

Question 10

What autoantibody may be seen in addisons disease?

Answer 10

anti- 21,hydroxylase

Question 11

How do sulfonylureas work? What are 2 side effects

Give an example

Answer 11

Bind to pancreatic beta cells ATP dependent K+ channel (closes it) –> increasing insulin release

weight gain + hypoglycaemia

Example: Gliclazide

Question 12

Give an exmaple of an SGLT2 inhibitor + how does it work

Answer 12

Reversibly inhibit sodium glucose co transporter 2 in renal prox conv tubule (reduce glucose reabsorption)

Example: dapagliflozin

Question 13

Which two diabetic classes can cause weight loss

Answer 13

SGLT2 inhibitors

GLP-1 analogues

Question 14

In T1DM patients with BMI >25 what should you consider adding into their medications?

Answer 14

metformin

Question 15

Causes of hypocalcaemia

Answer 15

vitamin D deficiency (osteomalacia)
chronic kidney disease
hypoparathyroidism (e.g. post thyroid/parathyroid surgery)
pseudohypoparathyroidism (target cells insensitive to PTH)
rhabdomyolysis (initial stages)
magnesium deficiency (due to end organ PTH resistance)
massive blood transfusion
acute pancreatitis

Question 16

Two main causes of hypercalcaemia. Give some other causes

Answer 16

1) Primary hyperparathyroidism
2) Malignancy (bone mets lytic, myeloma, PTHrP from SCC)

Other:
sarcoidosis/TB/histoplasmosis (all cause granulomas)
vitamin D intoxication
acromegaly
thyrotoxicosis
Milk-alkali syndrome
drugs: thiazides, calcium containing antacids
dehydration
Addison’s disease
Paget’s disease of the bone (usually normal initially)

Question 17

Complication of type 1 renal tubular acidosis

Answer 17

Hypokalaemia, Nephrocalcinosis + renal stones

Question 18

Complication of type 2 renal tubular acidosis

Answer 18

hypokalaemia, osteomalacia

Question 19

What is the commonest gene is defect in MODY?

Answer 19

HNF-1 alpha gene

Question 20

What diabetic medication increases risk of Fournier’s gangrene and how does it work?

Answer 20

SGLT-2 inhibitors

Inhibits sodium-glucose co-transporter –> prevents reabsorption of glucose and therefore increases urinary glucose excretion (n.b. this increases risk of urinary/genital infections)

Question 21

Give some adverse effects of SGLT-2 inhibitors

Give one benefit

Answer 21

UTI (secondary to glycosuria)
Normoglycaemic ketoacidosis
Increased risk of lower limb amputation

Benefit: weight loss

Question 22

What thyroid cancer is associated with Hashimoto’s?

Answer 22

Thyroid lymphoma

Question 23

What type of renal histological finding is seen diabetic retinopathy?

Answer 23

Nodular glomerulosclerosis + thickening of BM + Kimmelstiel-Wilson nodules

Question 24

What type of renal histological finding is seen in amyloidosis?

Answer 24

Apple-green birefringence under polarised light

Question 25

What is the treatment of hyperthyroid in pregnancy?

Answer 25

Propylthiouracil is used in the first trimester of pregnancy in place of carbimazole, as the latter drug may be associated with an increased risk of congenital abnormalities. At the beginning of the second trimester, the woman should be switched back to carbimazole

Question 26

What maternal free thyroxine level should a pregnant lady be kept at when treating hyperthyroid and why?

Answer 26

thyroxine levels should be kept in the upper third of the normal reference range to avoid fetal hypothyroidism

Question 27

What is the urinary sodium in SIADH?

Answer 27

> 20mmol/L

Question 28

What drugs might prevent absorption of levothyroxine (hence patient presenting with hypothyroidism despite being on treatment)?

Answer 28

ferrous sulfate/iron tablets + calcium carbonate

should be given 4 hours apart

Question 29

What is a contraindication for pioglitazones?

Answer 29

Previous bladder cancer (increases risk) or macroscopic haematuria (univestigated)

Heart failure

Question 30

What anti diabetic meds have extra benefit in those with CVD?

Answer 30

SGLT-2 inhibitors (gliflozins)

Question 31

What vision defect is seen in full scatter pan retinal photocoagulation in diabetic retinopathy?

Answer 31

Tunnel vision

Question 32

What is MEN I linked to?

Answer 32

parathyroid (95%): hyperparathyroidism due to parathyroid hyperplasia
pituitary (70%)
pancreas (50%, e.g. Insulinoma, gastrinoma)
also: adrenal and thyroid

Question 33

What is zollinger ellison syndrome?

Answer 33

excessive levels of gastrin, usually from a gastrin producing tumour