Contraception Flashcards
What are the routes of administration for contraceptives?
- Oral
- Transdermal patch
- Implants
- Nasal
- Vaginal
How is sex stored hormone transport influenced?
- Transport bound to Sex Hormone Binding Globulin or SHBG (except progesterone) and albumin. 1-2% is free
- SHBG upregulated by oestrogens to protect them against hepatic metabolism
How does storage affect sex steroid hormones?
- Increases the half life
- Sex steroid are easily sotred in fatty tissue because they are lipophilic. They complex into plasma membrane just like cholesterol
How are sex steroid hormones excreted?
-Metabolites are excreted through faeces and urine
How do sex steroid hormone work?
- ER-alpha and ER-beta for oestrogen
- PR-A and PR-B for progesterone
- AR-1 and AR-2 for testosterone
How does liver metabolism affect progesterone?
-Progesterone is almost totally metabolised in one pass through the liver
What are the types of oral contraceptive pills?
- COCP (Oestrogen and Progestin)
- POP (progestin only pill)
What are some examples of COCP?
1st Gen- Norethynodrel
2nd Gen -Levonorgestrel, Norethisterone
3rd Gen - Desogestrel, Gestodene, Norgestimate
4th Gen - Drospirenone (anti-mineralocorticoid, anti-androgen)
What are the effects of COCP?
- Suppression of Ovulation: inhibits FSH, LH
- Hold the hypothalamus and gonadotrophin in the ready to go state
- Holds ovary in non-dominant follicular state
- Makes cervical mucus which makes it more viscous
- Prevents secretory phase on the endometrium so endometrium remains atrophic
How does COCP work?
- Tricks the body into thinking that ovulation has already occurred
- Alters the lining of the womb
- Thickens the naturally occurring fluids in the cervix and prevents sperm from traveling into the womb
What are some side effects of COCP?
- Venous thromboembolism
- Myocardial infarction
- Hypertension
- Decrease glucose tolerance
- Increase risk of stroke in women with focal migraine
- Headaches
- Mood swings
- Cholestatic jaundice
- Increase incidence of gallstones
- Precipitate porphyria
How can drugs reduce the efficacy of COCP?
-Metabolised by CP450. COCP efficacy reduced by enzyme inducing drugs such as they increase production of P450 in liver
Which drugs reduce efficacy of COCP?
- Antiepileptics such as carbamazepine or phenytoin
- Antibiotics such as rifampicine and rifabutine
- Natural products such as St John’s Worts
How does Soya protein affect COCP?
- Soya protein products enhance oestrogen absorption and reduces its storage in adipose and muscle
- This cause half life to be reduced from 15 to 7 hours
What are some examples of progestin only pills?
- Levonorgestrel
- Norethisterone
- Ethynodiol Diacetate
- Desogestrel
How does POP work?
- Effecting the cervical mucous and the endometrium
- Needs receptor to work and receptor requitres oestrogen to form
- Works best when started in the follicular phase of menstrual cycle
What are some side effects of POP?
- Breast discomfort
- Changes in libido
- Depression
- Disturbance of appetite
- Dizziness
- Headache
- Menstrual irregularities
- Nausea
- Skin disorders
- Vomiting
What are the methods of emergency contraception and their period of use?
Up to 72 hours post coitus
-Levonorgestrel
Up to 120 hours
- Ullipristal acetate
- Cu2+ IUD
How does copper IUD work?
Prevents blastocyst attachment to endometrium
How does ullipristal acetate work?
Selective progesterone receptor modulator
How is Progestin Depot administered?
-Given every 12 weeks
Medroxy Progesterone Acetate
How does a progestin depot work?
Works by releasing progestin slowly into the body, suppressing oestrogen and other hormone levels
How does the progestin depot affect the reproductive system?
- Thickening of mucus from the neck of the womb
- Makes the lining of the womb thinner
- Prevents the ovaries releasing an egg
What is the advice given for missing one pill?
- Take the last (missed) pill immediately, even if this means taking two pills in one day.
- Continue taking the rest of the pack as normal.
- Take seven-day pill-free break as normal or, take (inactive) pills
What is the advice given for missing two pills anywhere in the pack or starting a pack 2 days late?
- Take the last pill immediately, even if this means taking two pills in one day.
- Continue taking the rest of the pack as normal.
- Use extra contraception for the following seven days
What is the advice given if there are seven or more pills left in the pack after the last missed pill?
-Finish the pack and take seven-day pill-free break as normal or, take (inactive) pills
What is the advice given if there are less than seven pills left in the pack after the last missed pill?
Finish the pack and start a new pack the next day; this means missing out the pill-free break or not taking your inactive pills
