Contraception 1 Flashcards
Describe the steps in the menstrual cycle
- On day one low levels of oestrogen stimulate the release of GnRH from the hypothalamus
- GnRH stimulates the pituitary to release FSH
- Follicles in the ovary grow and release oestrogen in response to increased FSH
- Oestrogen levels increase and stimulate proliferation of the endometrium
- Oestrogen levels reach a peak then stimulate the release of LH from the pituitary
- Ovulation occurs with 36 hours of the LH surge and the follicle walls then collapse
- Progesterone then becomes the primary hormone
- Progesterone levels peak 8 days post ovulation
- Progesterone promotes a secretory endometrium - preparing for implantation of a fertilised egg
- In addition to ovulation, oestrogen produces a thin watery muscles to facilitate sperm transport
- Post ovulation progesterone creates a thick sticky mucus which inhibits sperm transport
- Progesterone is also responsible for a slight rise in basal body temp
What are the long acting reversible contraceptive choices?
Levonorgestrel IUS
Copper coil
Progestogen implant
Progestogen injection
What are other forms of contraception?
CHC’s - pill, patch, ring
POP
Male and female condoms
Diaphragm and cap
Fertility awareness
Sterilisation
What oestrogen components do CHC’s contain?
Ethinylestradiol - 20 - 40 micrograms
Estradiol valerate
Mestranol - converted to ethinylestradiol in the gut
What Progestogen components do CHC’s contain?
Levonorgestrel
Norethisterone
Desogestral
Gestodene
Norgestimate
Nomesgestrol acetate
How do CHC’s work?
- They inhibit ovulation
- Both oestrogen and Progestogen work on the hypothalamic-pituitary axis preventing release of FSH and LH
- With no surge in FSH or LH ovulation does not occur
- Cause thickening if the cervical mucus producing a barrier to sperm
- Prevent implantation of a fertilised ovum due to decreased proliferation of the endometrium
Contraceptives should not be prescribed…
Generically
What type of preparation is not recommended in the NI Formulary?
Phasic - more complicated and no real benefit
What is the NI Formulary first choice for Monophasic standard strength CHC?
Rigevidon - 30 micrograms of ethinylestradiol and 150 levonorgestrel
1 daily for 21 days followed by a 7 day pill free interval
What is the NI Formulary second choice for Monophasic standard strength CHC?
Gederal 30/150 - 30 micrograms ethinylestradiol and 150 micrograms desogestral
Or
Cilique - 35 micrograms ethinylestradiol and 250 micrograms norgestimate
Or
Millimetre 30/75 - 30 micrograms ethinylestradiol and 75 micrograms gestodene
1 daily for 21 days then 7 day interval
What is the NI Formulary first choice for Monophasic low strength CHC?
Gedarel 20/150
Or
Millinette 20/75
How does the patch work?
- Avoids FPM
- Similar efficacy to oral CHC
- Produces plasma levels similar to that of oral CHC w/o peaks and troughs
- Apply to clean dry skin avoiding breast area
- Patches are worn for 7 days and then changed - repeated for 3 weeks then 7 days break
- Reserved for women where compliance is an issue
- Ethinylestradiol and norelgestromin
How does the vaginal ring work?
- Self insertion into vagina - remains in place for 21 days then patient has a 7 day break before inserting a new ring
- Avoids FPM
- Nuvaring - ethinylestradiol and etonogestrel
What are the tailored regimens?
Only work with monophasic designed to be taken 21/7
- Shortened HFI - 21 days - 4 day HFI
- Extended use - 9 weeks - 4 or 7 HFI
- Continuous use - continuous - no HFI
What are the risks with CHC?
- Increased risk of VTE
- risk factors = prolonged period of immobility, obesity, increasing age, fam history and smoking
- should be discontinued 4 weeks prior to elective surgery - Increased risk of cervical and breast cancer
- breast reduced after discontinuing CHC
- cervical risk associated with use >5 years
- cervical risk reduces over times and no longer present after stopping for 10 years - Arterial disease
- use associated with increased risk of stroke and MI
- avoid if following RF = obesity (BMI > 30kg/m2), mild - mod hypertension, diabetes mellitus, smoking, fam history - Migraines
- must ask an migraine history
- increased risk of ischameic stroke if migraine/migraine with aura - alt cont
Who can’t use CHC?
- Women with current breast cancer or last diagnosis in last 5 years
- Women over 50 years
- Hypertension - systolic >149 diastolic >90
- Breastfeeding/preg
- Migraine
- Less than 6 weeks post partum
- BMI >35KG/M2
- Personal history of VTE
- Family history of VTE
- History of thrombophillia
- CVD RF
- Current history if ischameic HD
- History of stroke/TIA
- Complicated HD
- History of atrial fib
What are the benefits of CHC?
- Reliable
- Reversible
- Reduced risk of anaemia
- Doesn’t interrupt sex
- Reduced risk of colorectal cancer
- Reduced risk of endometrial and ovarian cancer
- Less painful fibroids and functional ovarian cysts
- Less benign breast disease
- Reduce dysmenorrhea and menorrhagia
- Reduced PMT
- Reduced risk of pelvic inflammatory disease
- May improve acne
What are the S/E’s if CHC?
- Nausea - take after food, may need lower oestrogen
- Abdominal pain
- Breast pain/tenderness - typically resolves with 3 months - breast exam by GP - evening primrose oil/vit B6 may help provided no C/I
- Headache - rule out migraine - keep headache diary - if occurs in HFI consider shortened HFI
- Menstrual irregularities - pathology should be ruled out - may need higher dose of oestrogen if it doesn’t settle
- Change in lipid metabolism
- Hypertension - C/I - may need to change treatment
Why should people be discouraged from stopping and starting CHC?
VTE risk is highest in the months after starting or when restarting after a break of at least one month
Can CHC be used in perimenopause?
Yes in medically eligible women up til 50 as an alt to HRT for relief of menopausal symptoms, prevention of loss of bone mineral density and for contraception
If a patient is prescribed a teratogenic medicine that is not an enzyme inducer and no other inducers are co-prescribed what can they use?
Copper coil, etonogestral implant, levonorgestrel IUS
Oral CHC or POP or depot medroxyprogesterone with condoms
If a patient is prescribed a teratogenic medicine that is an enzyme inducer and other inducers are co-prescribed what can they use?
Copper IUD, Levonorgestrel IUS or depot medroxyprogterone with condoms
How do POP’s work?
- Thicken cervical mucus
- Delay ovum transport
- Inhibit ovulation
- Create an inhospitable endometrium for implantation
What are the benefits of POP?
- Very effective when used correctly
- Don’t need to stop prior to surgery
- No VTE risk
- Doesn’t interrupt sex
- Can be used in breastfeeding
- Suitable where CHC is C/I
- Desogestrel may help alleviate dysmenorrhea and mid cycle ovulation pain
What are the common S/E’s of POP?
- Headache
- Decreased libido
- Weight gain
- Acne
- Breast pain
- Irregular bleeding
- Small increased risk of ectopic pregnancy
If you vomit 2 hours after taking the pill…
Repeat the dose
Who can’t be on POP?
- current breast cancer or past diagnosis in the last 5 years
- severe cirrhosis
- liver disease
- stroke or ischaemic HD
- history of ectopic pregnancy
