Fertility Flashcards
What is clomiphene? What can it treat? Mechanism?
A fertility. Used to treat infertility caused by PCOS. It is anti-oestrogneic in the HP axis- binds to oestrogen receptors in the hypothalamus, hence blocking the normal negative feedback, increasing secretion of gonadotrophins and GnRH.
What is the aim of HRT for menopause?
To act a negative feedback on the HP axis and hence decrease the amount of circulating LH/FSH. This should reduce vasomotor symptoms. In addition, added oestrogen will alleviate osteoporosis effects.
Why is eostrogen given WITH progesterone in HRT?
To prevent endometrial hyperplasia.
Describe the 2 HRT formulations
Continuous combined or E every day with P every 12-14 days.
Describe the dosages associated with daily:
a) oral oestradiol
b) oral conjugated with equine oestrogen
c) Transdermal oestradiol
a) 1mg
b) 0.625mg
c) 50 mcg/day
What is ethinyl estradiol and why is it used?
A semi-synthetic oestroge. The ethinyl group protects the molecule from first pass metabolism, increasing its bioavailibilty in comparison to pure estradiol.
Name 4 general side effects of HRT.
Breast cancer, VTE, stroke and gallstones
What is the controversy regarding HRT and CHD?
Timing of exposure is important. ,10 since menopause or age 50-59 years, no excess risk.
This is because HRT prevents against formation of atherosclerosis but, if already present, can cause plaque instability.
What is tibolone? What is it used for? Mechanism? Positive? Negative?
A synthetic prohormone, used in HRT. Has oestrogenic and progestogenic (and weak androgenic) actions. Reduces fracture risk but increases risk of stroke.
What is raloxifene? What is it used for? 2 poitives? 2 negatives?
A selective oestrogen receptor modulator. Used in HRT. Reduces fracture risk and breast cancer risk (opposite effects) but increases risk of VTE and fatal stroke.
What is tamoxifen used for?
Anti-oestrogenic on breast tissue- used to treat oestrogen-dependent breast tumours.
Describe the common oral contraceptive. How does it work? Describe dosing schedule.
Ethinyl oestrogen+levonorgestrel. Together these have negative feedback effects at the hypothalamus and pituitary. The progesterone also thickens the mucus. Take for 21 days, stop for 7 days.
Give three examples of when an oestrogen contraceptive is contra-indicated.
Smoker, >35, migraine with aura
Describe the dosage of a progesterone only contraceptive
Must be taken at the same time each day because short duration of action and short half life.
What is the copper IUD? 1 condition and describe its mechanism.
An intrauterine contraceptive device- can be used as emergency contraception. Exclude pregnancy first, Affects sperm viability and function.
What is ulipristal? When can you take it? 2 actions.
An emergency contraception. Can be take up to 120 hours after intercourse. Delays ovulation by up to 5 days and impairs implantation.
