OCP Flashcards
What is the MoA of COCs?
Contain low dose oestrogen and moderate dose progestogen. Inhibition of hypothalamic and pituitary function leading to anovulation.
What are the norethisterone group of progestogens?
-norethisterone acetate
-ethynodiol acetate
-lynestrenol
Converted to norethisterone (NET) before exerting any contraceptive activity
What is the preferred progestogen? WHY?
Levonorgestrel. 10x more potent than NET, has less effect on the coagulative pathway.
What are the gestogens?
3rd gen progestogens -desogestrel -gestodene -norgestimate -cyproterone acetate Less androgenic than NET and LNG
What is the aim of COC commencement?
Provide good cycle control and effective contraception with the least side effects using a pill of the lowest dose
What is a suitable first choice COC?
Monophasic pill containing 30mcg ethinyloestradiol (EO) with levonorgestrel or norethisterone e..g Level ED, Nordette
What should high dose monophonic be reserved for?
50mcg oestrogen, high dose COC reserved for:
- breakthrough bleeding on low dose
- control or menorrhagia
- concomitant use of enzyme using drugs
- low dose pill failure
COC in epilepsy?
Use COC with high dose oestrogen (e.g. 50mcg)
COC in hirsute women?
Less androgenic preparation e.g. Diane-35, Estelle-35
COC in women 35+?
- Low dose monophonic (unless smoker)
- Controls hot flushes of perimenopause if continued until ~30y
- Cease pill around 51y, wait several weeks and check FSH/oestradiol
- if FSH high and oestradiol low, presume menopause
Absolute contraindications to COC?
- Pregnancy
- First 2 weeks post partum
- Hx of thromboembolic disease / thrombophilia
- Cerebrovascular disease
- Focal migraine
- Coronary artery disease
- Oestrogen dependent tumours
- Active liver disease
- Polycythemia
Relative contraindications to COC?
- Heavy smoking
- > 35 + smoking / other CV RFx
- Undiagnosed abnormal vaginal bleeding
- Breastfeeding
- 4 weeks before surgery, 2 weeks post
- GB/liver disease
- HTN / DM / hyperlipidemia
- Chloasma
- Severe depression
Circulatory disorders linked with COC use?
Venous: DVT, PE (+rare = mesenteric, hepatic, renal thrombosis)
Arterial: MI, thromboembolic/haemorrhagic stroke (+rare = retinal and mesenteric thrombosis)
What causes increased circulatory d/o risk in COCs?
Oestrogen content. Now reduced as doses have been reduced to 20mcg etc
Which cancers may be influenced by COC use?
Very low risk: cervix, breast
Protective: endometrial, epithelial ovarian