Oral contraceptives Flashcards
Describe the bioavailabilty of oestradiol
Oestradiol is well absorbed but has a low bioavailability (extensive first-pass metabolism)
What are some forms of oestrogen contraceptives/HRT?
- Oestrone sulphate (‘conjugated’ oestrogen)
- Oestriol
- Ethinyl oestradiol (the ethinyl group protects the molecule from first-pass metabolism)
What does a lack of oestrogen lead to?
Increased chance of osteoporosis and fracture
What can oestrogen contribute towards?
Breast growth (cancer) and CVS problems (VTE, stroke)
Describe the absorption and metabolism of progesterone
Progesterone is poorly absorbed and rapidly metabolised in the liver
How can progesterone be administered?
IM injection or depot preparation
Oral - norethisterone
What is the combined oral contraceptive?
This is a combination of an oestrogen (ethinyl oestradiol) and a progestogen (levonorgestrel or norethisterone)
What are the mechanisms via which the oral contraceptive suppresses ovulation?
- Feedback of oestrogen and progestogens on the hypothalamus and pituitary
- Progestogens thicken cervical mucus
How long is the COC taken for?
Taken for 21 days (or 12 weeks) and is then stopped for 7 days.
What are the side effects of oestrogens?
- Nausea.
- Breast (oestrogen dependant cancers)
- Headache
- Endometrium (causes proliferative effects)
- Increased weight (water retention and fat deposition)
- CVS problems (increased risk of fatal stroke and VTE (thrombosis moved to lungs))
When are progesterone only pills used?
When oestrogens are not a good idea – i.e. CVS problems, history of thrombosis, smokers, migraine
How are progesterone only pills administered?
- Long-acting preparations may be given by deep IM injection or via intra-uterine system
- Oral
They have short half lives and short duration of activity. For long acting use intrauterine
What are some emergency contraceptives?
How are they taken (doses)?
SE?
Levonorgestrel – combined E+P or P-only
- 2 doses 12 hours apart beginning ASAP within 72 hours of intercourse
- May cause nausea and vomiting
Copper IUD - Exclude pregnancy first. It works by affecting sperm viability and function
Ulipristal – up to 120 hours after intercourse
- Delays ovulation up to 5 days with anti-progestin activity. Impairs implantation
What is menopause and the age of onset?
Permanent cessation of menstruation resulting from the loss of ovarian follicular activity
Average age: 51 (45-55)
What is climacteric menopause?
The period of transition from predictable ovarian function through the postmenopausal years
What is premature ovarian failure/insufficiency and causes?
Menopause occurring before the age of 40 and occurs in 1% of women
- May be autoimmune or secondary to surgery, chemotherapy or radiation
Describe the levels of GnRH, LH, FSH and oestradiol in normal women
GnRH - high
LH/FSH - high
Oestradiol - high
Describe the levels of GnRH, LH, FSH and oestradiol in menopausal women
GnRH - high
LH/FSH - high
Oestradiol - low
What are the symptoms of menopause?
- Hot flushes
- Sleep disturbance
- Depression
- Urogenital atrophy
- Decreased libido
- Joint pain (lack of oestradiol)
disappear with time
What are the complications of menopause?
Osteoporosis:
- Oestrogen deficiency leads to loss of bone matrix.
- Loss of 1-3% of bone mass/year and have 10x increase risk of fracture.
Cardiovascular disease:
- Women are protected from CVS disease before the menopause but have the same risk as men by the age of 70.
What is the HRT for menopause?
- HRT – oestrogen + progesterone – to prevent endometrial hyperplasia
- Can be given oral, transdermal, transvaginal
- HRT can be cyclical: oestrogen given every day, and progesterone is given for the last 12-14 days
- Or HRT can be continuous combined: continuous oestrogen and progestogens, all the time
Which menopausal women are given oestrogen only treatment and why are they given HRT?
Women that have had hysterectomies (as no endometrium!)
Control symptoms – i.e. control vasomotor symptoms of hot flushes.
What is used in the treatment & prevention of postmenopausal osteroporosis?
Give examples
SERMs – Selective Oestrogen Receptor Modulators:
E.G. Raloxifene (Tissue-selective – oestrogenic in bone and anti-oestrogenic in breast and uterus)
Reduces risk of: vertebral fractures and breast cancer.
Increases risk of: fatal stroke, VTE.
Does not affect vasomotor symptoms.
Which drug can be used in breast cancer treatment?
Tamoxifen (anti-cancer drug):
Anti-oestrogenic in breast tissue.
Used to treat oestrogen-dependant breast tumours and metastatic breast cancers.
