11. Sex Hormones Flashcards
What are the functions of oestrogen and progesterone?
Oestrogen: growth of the endometrium . Can decrease bone resorption and raises HDL, lowers LDL
Progesterone: prepares the endometrium for implantation and maintains the pregnancy. And growth of breasts
What are sex steroid hormones bound to?
All are bound to SHBG and albumin (except progesterone). They are also easily stored in adipocytes and the brain as they are lipophillic .
What are the nuclear receptors for oestrogen, progesterone and androgen?
Oestrogen: ERa and ERb
Progesterone: PR-A and PR-B
Androgen: AR-1 and AR-2
Is this pill taken orally only?
No, can her oral, transdermal, implants, nasal and vaginal
What are the 2 types of oral contraceptive pill?
COCP: oestrogen and progestin (administered in 3 ways)
POP: progestin only pill (administered in lots of ways)
Name some side effects of oestrogen
- nausea and vomiting
- breast tenderness
- water retention
- increases blood coagulability
- venous thromboembolism
- impaired glucose tolerance
- endometrial, breast, ovarian cancer
Name some side effects of progesterone
- weight gain Fluid retention -nausea and vomiting -acne -irritability
Name some side effects of testosterone
- male secondary sex characteristics e.g. hirsutism
- acne
- voice changes
- increased aggression
- increased risk of atherosclerotic disease
What are the 3 combinations of the COCP?
Monophysite, biphasic or triphasis.
1) Monophasic: Each tablet contains a fixed amount of oestrogen and progestin for 21 days
2) biphasic: each tablet has fixed amount of oestrogen and the amount of progestin increases in the 2nd half of the cycle (21 days)
3) triphasic: the amount of oestrogen is fixed or variable and the amount of progestin increases in 3 phases. 21 days + 7 days placebo
What is the mode of action of the COCP?
It is a slow release agonist that:
- suppression of ovulation: inhibits FSH, LH (tricks body into thinking ovulation has already occurred)
- makes cervical mucus more viscous (preventing sperm from travelling)
- prevents the secretory phase , holds it in strophic state (preventing fertilised egg from latching on to develop)
Remember that for the drug to work, the receptor needs to be present and because the progesterone receptor expression is dependent upon oestrogen action, therefore oestrogen must be supplied either continuously or prior to the progestin.
What are the ADRS of the COCP?
- venous thromboembolism
- myocardial infarction
- headaches
- hypertension
- mood swings
- impaired glucose tolerance
- risk of stroke in women who have focal migraines
- cholestatic jaundice
- increased incidence of gallstones
- precipitate porphyria
Which drugs can affect COCP?
- metabolised by CYP450
-so the efficacy will be reduced by P450 inducing drugs (PC
BRAS)
-soya protein products - enhanced oestrogen absorption and reduce it storage in adipose causing its half lie to be reduced from 15 to 7 hours
What is the progestin only pill (POP)? How does it work?
It is 28 days of progestin only e.g. norethisterone or levonorgestrel.
It works by thickening the cervical mucus and can thin the endometrium and works best when started in the follicular phase of the menstrual cycle.
What is a missed pill?
When it has been more than 24 hrs since you took that pill
What do you do if you have missed one pill?
- take the last pill immediately even if this means taking 2 pills in one day
- continue taking the rest of the pack as normal
- take your 7 day pill free break as normal or take the inactive pills
