Contraception Flashcards
(27 cards)
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
