Flashcards in OCP Deck (27):
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?
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
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?
-First 2 weeks post partum
-Hx of thromboembolic disease / thrombophilia
-Coronary artery disease
-Oestrogen dependent tumours
-Active liver disease
Relative contraindications to COC?
->35 + smoking / other CV RFx
-Undiagnosed abnormal vaginal bleeding
-4 weeks before surgery, 2 weeks post
-HTN / DM / hyperlipidemia
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
Mx breakthrough bleeding on low dose COC?
Usual to have breakthrough bleeding in first 2 months. If minor, continue. If major, cease and start new pill, usually with 50mcg ethinyloestradiol
Advice when starting pill?
-Periods often become shorter and lighter
-No break is necessary
-Drugs that may affect pill: antacids, purgatives, vitamin C, antibiotics, anticonvulsants
-D/V may reduce effectiveness: if vomits within 2h taking pill, take another active pill
-Return yearly for review
Advice re missed pills?
Just keep going: take a pill as soon as possible then resume usual schedule
IF >2x20 or >3x30 EO pills are missed, use condoms / abstinence for 7 days
7 day rule for missed or late pill?
-take forgotten pill asap, even if you take 2 the next day
-if >12h late, increased risk of pregnancy so use another contraceptive method for 7 days
-if these 7d run beyond last hormone pill in pack, miss the inactive pills and start next pack
-you may miss a period (at least 7 hormone tablets should be taken)
Delaying a period?
Skip sugar pills, continue taking hormone pills until end of next pack
What is the mini pill?
Progestogen only pill e.g. levonorgestrel 30mcg/day
Side effects mini pill?
No serious AEx. Compliance a problem due to cycle irregularity, irregular bleeding.
Often decreases cycle length
Indications for POP?
-CIx to or intolerance of oestrogen (migraines, DM, chloasma, lactation, HTN)
What is the injectable contraceptive?
Depo-provera. Only IM contraceptive in Aus.
150mg injection every 12 weeks
What is the implanon?
Subdermal contraceptive implant containing etonogestrel (progestogen). Inhibits ovulation and has anti mucous effect.
Absolute IUD contraindications?
-Known or suspected pregnancy
-Undiagnosed genital tract bleeding
-Severe uterine cavity distortion