Endo

Question 1

4 types of drugs used in the treatment of hyperthyroidism

Answer 1

Thionamides
Radioiodine
Beta blockers
Potassium iodide

Question 2

2 examples of thionamide in the treatment of hyperthyroidism?

Answer 2

propylthiouracil (PTU)
carbimazole (CBZ)

They work by inhibiting thyroperoxidase which normally iodinates the tyrosine residues on the thyroglobulin

Question 3

radioactive half life of radioiodine

Answer 3

8 days

Question 4

4 causes of ovarian failure

Answer 4

discontinuity/damage/dysgenesis

1. premature ovarian insufficiency (discontinuity- early menopause)
2. chemo
3. ovariectomy
4. Turner’s (dysgenesis)

Question 5

What enzyme does metyrapone inhibit

Answer 5

inhibits 11 beta hydroxylase (involved in cortisol and corticosterone synthesis). used in treatment of cushings

Question 6

name a MR receptor antagonist used to treat conn’s syndrome (high aldosteron) and a better version of the drug

Answer 6

spironolactone

eplerenone =better version of spironolactone due to less side effects

Question 7

spironolactone side effects

Answer 7

side effects due to blocking progesterone receptors (menstrual irregularities) and androgen receptors (gynaecomastia)

Question 8

What can cause vitamin D excess

Answer 8

excessive treatment with active metabolites of vitamin D eg Alfacalcidol

granulomatous diseases such as sarcoidosis, leprosy and tuberculosis (macrophages in the granuloma produce 1a hydroxylase)

Question 9

What drug would you give to replace calcitriol in patients with renal failure

Answer 9

alfacalcidol

Question 10

What drug would you give to replace calcitriol in patients without renal failure

Answer 10

Ergocalciferol 25 hydroxy vitamin D2
Cholecalciferol 25 hydroxy vitamin D3
Both of the above can be converted to 25-OH-D3 in the liver after the first hydroxylation (see slide 6 of calcium control lecture)

Question 11

2 iatrogenic causes of osteoporosis

Answer 11

1. Prolonged glucocorticoid use

2. heparin use

Question 12

4 endocrine causes of osteoporosis

Answer 12

1. Hypogonadism
2. Cushing’s
3. Hyperthyroidism
4. Primary hyperparathyroidism

Question 13

Bisphosphonates unwanted effects

Answer 13

osteonecrosis of jaw
oesophagitis
Atypical fractures
- may reflect over-suppression of bone remodelling in prolonged bisphosphonate use. Ie the drug has caused a lot of imbalance in the ying yang of the bone turnover between osteoclasts and osteoblasts and so it causes atypical fractures

Question 14

treatment of paget’s

Answer 14

bisphosphonates

analgesia

Question 15

name the first compound of the vitamin D synthesis/activation pathway

Answer 15

7 dehydrocholesterol (in skin)

Question 16

Define infertility

Answer 16

inability to conceive

1 year of regular unprotected Sex

Question 17

PRIMARY hypogonadis,- list some congenital and acquired causes

Answer 17

congenital- klinefelter

acquired- testicular torsion/chemo

Question 18

What investigations would you make in a male hypogonadal patient

Answer 18

1.check LH, FSH andtestosterone levels:

–If all low&raquo_space;suggests secondary hypogonadism&raquo_space; pituitary MRI

2. Check prolactin levels (hyperprolacinaemia could cause this)
3. Sperm count

–Azoospermia = absence of sperm in ejaculate

–Oligospermia = reduced numbers of sperm in ejaculate

Question 19

How would you treat hyperprolactinaemia

Answer 19

d2 agonist
cabergoline
bromocriptine

Question 20

Testosterone is heavily plasma protein bound and it can be converted to other hormones in various tissues. State two products that testosterone can be converted to and the enzymes responsible for these conversions.

Answer 20

Converted by 5-alpha-reductase to dihydrotestosterone (DHT), which acts on androgen receptors

Converted by aromatase to 17-beta-oestradiol (E2), which acts on oestrogen receptors

MECHANISM OF ACTION OF DHT / E2 is via nuclear receptors

Question 21

Primary and secondary amenorrhea definitions

Answer 21

Primary Amenorrhoea = failure to develop spontaneous menstruationby the age of 16 years

Secondary Amenorrhoea = absence of menstruation for 3 months in a woman who has previously had cycles

Question 22

What can androgen excess (eg high testosterone) do to menstrual cycles?

Answer 22

Can disturb/stop the cycles. Hence androgen excess (due to eg gonadal tumours can cause amenorrhea)

Question 23

PCOS diagnostic criteria

Answer 23

need 2 of the following:

• polycystic ovaries on USS
• oligo- / anovulation
• clinical / biochemical androgen excess (causes hirsutism)

Question 24

What hormone in the hypothalamus can stimulate prolactin

Answer 24

Thyrotrophin releasing hormone (TRH)

Question 25

PCOS treatment

Answer 25

METFORMIN – insulin sensitiser

CLOMIFENE – anti-oestrogenic effects in the hypothalamo-pituitary axis – binds to oestrogen receptors in the hypothalamus thereby blocking the negative feedback –> increased GnRH and gonadotrophin secretion

GONADOTROPHIN THERAPY as part of IVF treatment