Oral contraceptives Flashcards
What are the 4 fertility regulating hormones?
Gonadotrophin releasing hormone (GnRH) FSH - gonadorophin LH - gonadotrophin Progesterone Oestrogens
What are the 2 phases of the menstrual cycle?
Follicular phase (1-14) Luteal phase (14-28)
What days are ‘bleeding’?
1-5
Which hormone thickens the endometrial lining?
Estrogen
Which hormone maintains the thickening of the endometrial lining?
Progesterone
What do synthetic steroids do to progesterone and estrogen?
Increase their half lives
What are the two types of oral contraceptives?
- Combined oral contraceptives (COC’s)
2. Progestin-only contraceptive (less common)
What is the estrogen in in COC’s usually?
Ethinyl estrodiol
Progestin varies in 2nd and 3rd generation pills. Which generation is highly effective and more common?
3rd generation pills
What is the usual cause of a decreased success rate in using the oral contraceptive?
Lack of compliance by users
What are the 3 hormonal variants in the COC pills?
- Monophasic: constant dose of estrogen and progestin throughout monthly cycle
- Biphasic: estrogen constant, progestin increased in the second half of the cycle
- Triphasic: does of estrogen higher in middle part of cycle or remains constant. Progestin increases in 3 steps during the cycle
What type of pill is the Mini Pill?
Progestin-only pill.
How does the mini pill offer increased safety?
high doses of estrogen are associated with CV adverse side effects, so having progestin only is safer in a lot of ways.
Suitable for breast feeding women (no estrogen)
Smokers prescribed it if they don’t want to stop smoking.
How is the mini pill slightly less effective than COC’s?
It’s taken every 24 hours without a break, with only a 3 hour window for missed pills. NEED COMPLIANCE!!!
How do oral contraceptives help to reduce the chances of getting pregnant?
- prevent ovulation
- Thicken cervical mucus to stop sperm
- Reduce motility of fallopian tubes
- Thin endometrium to prevent implantation
What are the hormonal effects of estrogen?
Prevents release of FSH by neg. feedback on Ant. Pituitary (suppresses development of follicle)
What are the hormonal effects of progestin?
Inhibits secretion of LH and FSH (neg. feedback) and suppresses ovulation.
Increases thickness of cervical mucus.
What are common side effects of COC’s?
Mood changes, depression, headaches
Fluid retention, weight changes
Nausea, vomiting
Cramps, breakthrough bleeding
What are serious but rare side effects of COC’s?
Risk of breast cancer
Hypertension
Deep vein thrombosis
CV disease
What are the 2 main big health benefits of COC/s?
Decreased risk of ovarian cancer and endometrial cancer.
What are oral contraceptives metabolised by?
CYP450 enzymes
What is the emergency contraceptive pill?
Combo high dose ethinyl estradiol and progestin OR progestin only.
Given within 72 hours of sex. Requires second dose 12 hours later.
What does the ECP do?
Prevents ovulation and implantation
What is the abortion pill called?
RU 486, Mifepristone
