Contraception and HRT Flashcards
What does the combined oral contraceptive pill contain?
Oestrogen mimic and progestin
What does the mini-pill contain?
progesterone only
Name examples of synthetic oestrogen and progesterone and what are the molecular targets of these synthetic oestrogen and progesterone?
ER1alpha and ERbeta (Ethinylestrasiol)
PR-A and PR-B (Desogestrel and Levonorgestrel)
Describe the molecular mechanism of 17-B-estradiol (E2) in influencing gene exp of oestrogen.
E2 diffuses across cell membranes, binds to ERalpha
Binding of hormone drives receptor activation via dissociation from HSP90
Active receptor dimerises and enters nucleus
Influences gene expression by binding to ERE
What is the primary outcome of oral contraceptives?
Suppression of ovulation
Progesterone - disrupt fertilisation and implantation
Inc levels of oest and prog -> -ve feedback on hypothalamus and ant pituitary -> suppress FSH and LH synthesis -> ovulation cannot occur
What is in the morning after pill?
Progestin - often Levonorgestrel at high dose
What are the effects of asynchronous high level of progesterone on endometrium?
Inhibits endometrial gland development making implantation less favourable
Thickens cervical mucus - inhibits sperm motility
What are common adverse effects of oral contraceptives?
Nausea and vomiting, diarrhoea - effects ingestion of oral drug
Bleeding, spotting
Inc risk of cardiovascular problems
Inc risk of breast cancer
What can the oral contraceptive be used for beyond contraception?
Endometriosis
Dysmenorrhoea (painful periods), Menorrhagia (heavy bleeding)
Acne
Progesterone and progestins - reduce risk of endometrial cancer (orally and with IUS)
What does the vaginal ring do?
Progestin and oestrogen
Polymer with slow and continuous release of ethinylestradiol and etonogestrel
Inserted for 21 days with 7 days break
What does the IUS do? What is an alternative name?
Mirena
Progestin-releasing polymer (lasts <5 years)
typically releases levonorgestrel
Fewer side effects than pill
What is an implant? (upper arm)
Subcutaneous polymer implant
releases etonogestrel at a slow and stead pace
lasts for 3 years
Placed under skin of upper arm in a procedure using local anaesthetic
What does HRT contain?
low doses of oestrogen - natural estradiol
What are the routes of administration of HRT?
Orally via daily tablets
Transdermal patches (2 weeks)
Subcutaneous estradiol implants - pellets implanted subcutaneously (6 months) progestin taken orally
Topical estradiol creams - treat urogential symptoms e.g. vaginal atrophy and dyspareunia
What are the benefits of HRT?
Improve hot flushes and night sweats
Improve urogenital symp: vaginal atrophy, vulvovaginitis, dysuria
Reduces risk of osteoporosis and fractures
