Endo Flashcards
4 types of drugs used in the treatment of hyperthyroidism
Thionamides
Radioiodine
Beta blockers
Potassium iodide
2 examples of thionamide in the treatment of hyperthyroidism?
propylthiouracil (PTU)
carbimazole (CBZ)
They work by inhibiting thyroperoxidase which normally iodinates the tyrosine residues on the thyroglobulin
radioactive half life of radioiodine
8 days
4 causes of ovarian failure
discontinuity/damage/dysgenesis
- premature ovarian insufficiency (discontinuity- early menopause)
- chemo
- ovariectomy
- Turner’s (dysgenesis)
What enzyme does metyrapone inhibit
inhibits 11 beta hydroxylase (involved in cortisol and corticosterone synthesis). used in treatment of cushings
name a MR receptor antagonist used to treat conn’s syndrome (high aldosteron) and a better version of the drug
spironolactone
eplerenone =better version of spironolactone due to less side effects
spironolactone side effects
side effects due to blocking progesterone receptors (menstrual irregularities) and androgen receptors (gynaecomastia)
What can cause vitamin D excess
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)
What drug would you give to replace calcitriol in patients with renal failure
alfacalcidol
What drug would you give to replace calcitriol in patients without renal failure
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)
2 iatrogenic causes of osteoporosis
- Prolonged glucocorticoid use
2. heparin use
4 endocrine causes of osteoporosis
- Hypogonadism
- Cushing’s
- Hyperthyroidism
- Primary hyperparathyroidism
Bisphosphonates unwanted effects
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
treatment of paget’s
bisphosphonates
analgesia
name the first compound of the vitamin D synthesis/activation pathway
7 dehydrocholesterol (in skin)
Define infertility
inability to conceive
1 year of regular unprotected Sex
PRIMARY hypogonadis,- list some congenital and acquired causes
congenital- klinefelter
acquired- testicular torsion/chemo
What investigations would you make in a male hypogonadal patient
1.check LH, FSH andtestosterone levels:
–If all low»_space;suggests secondary hypogonadism»_space; pituitary MRI
- Check prolactin levels (hyperprolacinaemia could cause this)
- Sperm count
–Azoospermia = absence of sperm in ejaculate
–Oligospermia = reduced numbers of sperm in ejaculate
How would you treat hyperprolactinaemia
d2 agonist
cabergoline
bromocriptine
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.
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
Primary and secondary amenorrhea definitions
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
What can androgen excess (eg high testosterone) do to menstrual cycles?
Can disturb/stop the cycles. Hence androgen excess (due to eg gonadal tumours can cause amenorrhea)
PCOS diagnostic criteria
need 2 of the following:
- polycystic ovaries on USS
- oligo- / anovulation
- clinical / biochemical androgen excess (causes hirsutism)
What hormone in the hypothalamus can stimulate prolactin
Thyrotrophin releasing hormone (TRH)
PCOS treatment
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
