contraceptives in practice Flashcards
what are the two main classes of hormonal contraceptions?
Combined hormonal contraception
progesterone only contraceptives
what does the combined hormoneal contraception contain?
both oestrogen and a progesterone
what is in the progesterone only contraceptives?
contain only a progesterone of which there are many different types
what forms do combined hormonal contraceptives come in?
tablets
vaginal ring
patches
what forms do progesterone only contraceptives come in?
progesterone only pills
parental prep- depot injection inplant
coil
what other methods of contraception are available?
copper-iud, barrier methods
non-hormonal
before ovulation what hormones is there a peak of?
LH AND FSH
what is the primary mechanism of CHC’s?
inhibit ovulation
The oestrogen and progestogen components of the CHC’s
act on the hypothalamo-pituitary ovarian axis to suppress LH
and FSH production.
• Oestrogen
• With no surge in LH and FSH to stimulate the ovaries,
ovulation does not occur.
also cause change in the cervical mucus which act as a barrier to sperm- thinning of the endothelium reduces the chance of implantation
how does the endometrium become fragile?
o Oestrogen causes the endometrium to proliferate and
grow which is opposed by the progestogen which
prevents hyperplasia (excessive growth) of the
endometrium
o The resulting endometrium is thin, fragile and prone
to bleeding
what effect does the 7 day pill free interval have?
causes oestrogen and progestogen concentrations to fall.
• Causing the oestrogen-primed endometrium to slough,
mimicking menstruation.
• Also known as a withdrawal bleed.
how do COC prep differ?
1-type of progesttogen
2-how the dose varies over the menstrual cycle
3-the dose/strength of oestrogen
4-presence or absense of pill-free interval
what are the different components of the COC?
Oestrogen component – Typically the synthetic
oestrogen ethinlyestradiol but some contain mestranol.
• Progestogen component - eg. levonorgestrel,
norethisterone, desogestrel, gestodene, or
drospirenone
how are the progestogen components grouped?
First: norethisterone
• Second: levonorgestrel (LNG)
• Third: desogestrel, gestodene, norgestimate*
Newer/other: drospirenone (DRSP), dienogest,
nomegestrol acetate.
what are the differences in the COC preparations?
COC preparations differ according to how the doses vary over the
menstrual cycle.
• Monophasic COCs – Are first line and the amount of oestrogen and
progestogen in each active tablet is constant throughout the cycle (most
commonly prescribed)
• Phasic COCs — the amounts of oestrogen and progestogen vary over the 21
day cycle.
what are the different phasic COC?
• Biphasic COCs — contain two different sets of active tablets. E.g
Binovum,
• Triphasic COCs — contain three different sets of active tablets. E.g
Trinordiol
• Quadraphasic COCs — contain four different sets of active tablets.
what is a low strength COC preparation?
Low-strength - 20 micrograms of ethinylestradiol.
• Useful if risk factors for circulatory disease
• Can cause disrupted bleeding patterns
what is a standard strength preparation?
Standard-strength - 30–35 micrograms of ethinylestradiol in monophasic
COCs and 30–40 micrograms ethinylestradiol in phased preparations.
• Mestranol 50 microgram equates to 35 microgram ethinylestradiol
what dose of oestrogen is recommended?
the lowest dose of oestrogen to provide good cycle control should be
used.
• Generally 30-35micrograms of ethinylestradiol in most patients
how does COC’s differe in a pill-free interval?
Standard preparations
• Most COCs are packaged as calendar strips of 21 active tablets.
• One tablet is taken daily for 21 days then no tablet is taken
during the following 7 days (Hormone free interval (HFI)).
• HFI – when the patient isn’t taking any hormone.
ED Preparations
• Useful when compliance is a concern
• Taken continuously with no HFI
• 21 active tablets and 7 inert/placebo tablets (taken Days 22-28)
to allow withdrawal bleed.
what COC is used for 28 days continuously?
Qlaira®
• Quadriphasic pill used in treatment of heavy menstrual bleeding
Start on day one of the cycle
• 28 tablets and taken continuously
• Missed pills rules differ significantly
• Need to be aware of this in practice.
what is Dianette used for?
• Co-cyprindiol- Cyproterone acetate and ethinylestradiol 2000/35
• Not indicated for use solely as an oral contraceptive
• Used in women who require oral contraception and suffer
from acne or hirsutism
• Carries an Increased risk of venous thromboembolism (VTE)
how does one initiate monophasic COC?
Day 1 up to and including day 5 of menstrual cycle
• No additional contraception is needed.
• Ideally start on day 1 of the cycle.
Day 6 of menstrual cycle onwards
• Additional precautions are required for 7 days after starting (9
days for Qlaira®)
Postpartum
• up to and including day 21 postpartum. – no additional
contraception required
• (if not breast feeding and no VTE risk)
Day 1 up to and including day 5 of menstrual cycle
• No additional contraception is needed.
• Ideally start on day 1 of the cycle.
Day 6 of menstrual cycle onwards
• Additional precautions are required for 7 days after starting (9
days for Qlaira®)
Postpartum
• up to and including day 21 postpartum. – no additional
contraception required
• (if not breast feeding and no VTE risk)
what is the benefit in tailoured regimes?
Day 1 up to and including day 5 of menstrual cycle
• No additional contraception is needed.
• Ideally start on day 1 of the cycle.
Day 6 of menstrual cycle onwards
• Additional precautions are required for 7 days after starting (9
days for Qlaira®)
Postpartum
• up to and including day 21 postpartum. – no additional
contraception required
• (if not breast feeding and no VTE risk)
if used perfectly/typically what is the risk that CHC would fail?
perfectally-<1%
typically- rate is 9%