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%
what is the action for missed pill dependent on?
When the contraception has been missed i.e time since last active pill was taken. • How many pills the patient has missed • Where they are In the cycle (pack) • Which pill the patient is taking
what do you do if COC one pill is late?- less than 24 hr/ one pill has been missed- more than 24 but less than 48 hr?
take the late or missed pill asap
continue the remaining pills at usual time
no additional contraceptives is needed
what do you do if COCone pill is late more than 48 hrs?
take the most recent pill as soon as possible- ant other missed pills should be disgarded
continue taking the remaining- even if that means 2 on same day
use additional contraception/ avoid sex for 7 days
if pills were missed in the last week- ommit the hormone free-interval by finishing the pills in current pack and starting new one next day
when would the patient be considered at risk after a late or missed pill?
if more than 7 days are missed in any week of taking the pill
what should be done when it has been 9 complete days or more since the last active pill was taken when restarting the pill?
When the contraception has been missed i.e time since last active pill was taken. • How many pills the patient has missed • Where they are In the cycle (pack) • Which pill the patient is taking
what are some of the advantages of COC?
- More effective at preventing pregnancy than barrier methods
- Menstrual bleeding is usually regular, lighter, and less painful
- Reduced risk of cancer of the ovary, uterus, and colon.
- Reduced severity of acne in some women.
- Reduced incidence of pre menstrual tension (PMT)
- Reduced the risk of ovarian, endometrial and colorectal cancer
- Normal fertility returns immediately after stopping the COC
what are some of the disadvantages of COC?
temporary ADRs
• Blood pressure may increase.
• No protection against STIs; people at risk of STIs are advised
to use condoms in addition to the COC.
• Less effective than long-acting reversible methods of
contraception (such as progestogen-only implants or
injectables, copper intrauterine devices, levonorgestrelreleasing intrauterine system)
what kind of drug interactions occur with COC’s?
Enzyme inducing antibiotics eg. Rifampicin or rifabutin
what should be advised with short-term treatment of enzyme inducing antibiotics while taking COC?
• Women should always be advised to change to an alternative
method where possible
• However, use of an alternative barrier method whilst taking and
for 28 days (4 weeks) after stopping can be considered.
• Breakthrough bleeding can occur as a complication and indicates
low serum oestrogen concentrations.
what is advised with longer term treatment - longer than 2 months?
Change to an alternative method of contraception
what effect do non-enzyme prodicing antibiotics have?
most broad spectrum antibiotics are non-enzyme inducing and do not require any special precautions
no additional contracteption unless medication causes vomiting/ diarrhoea
what are other enzyme inducing drugs that may cause drug interactions with COC?
• Antiepileptics -carbamazepine, phenobarbital, phenytoin, topiramate
• Lamotrigine - not an enzyme-inducer…..but COC can increase
clearance of lamotrigine leading to poor seizure control.
• Herbal remedies — St John’s Wort….available OTC!!
what is the advised treatment advise with other enzyme inducing drug interactions with COC?
short term:• Advice is to change method of contraception if possible or
• Continue to use COC with an extended/tricycling regimen and avoid
sexual intercourse or use a barrier method while using and for 28 days
after
long term: Change to an alternative method of contraception
how does vomiting and diarrhoea affect COC? what should be done?
• Absorption of the oral contraceptives can be affected!
• If vomiting occurs (for any reason) within 3 hours of taking a pill
then take another pill ASAP
what should you do if vomiting or severe diarrhoea occurs for> 24 hours?
• To follow the instructions for missed pills, counting each day of
vomiting and/or diarrhoea as a missed pill.
• To avoid sexual intercourse or use a barrier method of
contraception (such as condoms) during the illness interval and for
7 days afterwards.
• If the illness occurs while taking the last 7 tablets, omit any pill-free
period (or inactive tablets) and start the next cycle immediately!!!
what are the risks that COC cause?
MI and stroke
increased risk of VTE
breast cancer/ cervical cancer
age
how does age increase COC risk?
Over 35yrs and smoker
• Avoid >50yrs
• Can be used up to 50 when no other risk factors are
present.
what are the 4 categories which apply to the risk oc contraption?
• Category 1: no restriction to use.
• Category 2: advantages of use of the method of contraception
generally outweigh the risks.
• Category 3: risks generally outweigh advantages. Use is not usually
recommended unless other methods are not available or not
acceptable.
• Category 4: use of the contraceptive method would result in
unacceptable risk to health. COC prescribing contraindicated.
what are the contraindications for COC?-category 4
UKMEC Category 4 (unacceptable health risk)
•Severe or multiple risk factors for arterial disease
•VTE
•Migraine with aura
•Smoker ≥ 15 cigarettes per day and ≥ 35 years
what are the risk factors- category 3
- 1st degree relative < 45 years with a history of VTE
- BMI ≥ 35
- Smoker < 15 cigarettes per day or stopped in last year and ≥ 35 years
- Symptomatic gall bladder disease
- Adequately controlled hypertension
- Diabetes with nephropathy/retinopathy/ neuropathy
- Breastfeeding between six weeks and six months post partum
what are the unwanted effects of COC?
• Temporary adverse effects may include breast tenderness, headaches and nausea. • Breakthrough bleeding (BTB) can occur. weight gain mood changes
what happens if the side effects of COC’s do not settle over first 3 months?
an alternative CHC or
an alternative form of contraception may be tried
what should someone do if they develop a mingrane while using COC?
increases risk factor for CV disease
if it is with aura- c/i
without aura- ukmec 2
new onset - benefits usually outwight risk
or alt method- or progestogen only considered
what are the reasons you would stop COC immediately?
an alternative CHC or
an alternative form of contraception may be tried
what is the combined contraceptive patch in the UK and how should it be used?
• Only combined hormonal patch in the uk- Evra® patch
• Contains ethinylestradiol and norelgestromin.
• Only one patch should be worn at a time applied to clean, dry,
lotion-free, healthy, hairless skin.
• Do not apply to the breasts or to red, broken, or inflamed
skin.
check daily to make sure patch is not detached
what are the detached patch rules?
• 1 patch applied once weekly for three weeks then 7-day patch
free interval
• If patch partly detached < 48 hours
• Re-apply the patch and no additional precautions
needed
• If patch detached > 48 hours or not sure when detached
• Start a new cycle of the patch
• This is now week 1 of the patch cycle. It is also the
new day of the week for changing patches and for
starting new patch cycles.
• Abstain or use a barrier method for the next 7 days
what is the MOA for pops?
• Traditional POPs.
• The primary mechanism of action is to alter the cervical mucus
making it more viscous and impenetrable to sperm.
• Suppression of ovulation occurs in some women.
• Less reliable in traditional POP’s where ovulation is
inhibited in only 60% of cycles
• Desogestrel-only pill works
• Primary mechanism of action is inhibition of ovulation
• Desogestrel inhibits ovulation in 97% of cycles
• Alteration of cervical mucous can still occur.
how should POPs be taken?
Traditional POPs
• One to be taken daily continuously without a break
• 3 hour window for missed pills
• Norethisterone 350 micrograms - Micronor® and Noriday®.
• Levonorgestrel 30 micrograms - Norgeston®.
• Desogestrel only pill
• One to be taken daily continuously without a break
• 12-hour window for missed pills
• Desogestrel 75 micrograms - Cerazette®, Aizea®, Cerelle® and
Nacrez®
when should desogestrel only pill be given?
- Often give desogestrel first line in:
- Younger patients <35 years2
- If likely compliance issues with taking traditional POP
when should POP’s be given?
when oestrogens are c/i in the following: • Older women • Age up to 55 years (natural loss of fertility assumed) • VTE (or past history of) • Smokers • Hypertension • Valvular heart disease • Diabetics • Migraine sufferers • Breast feeding
how do you initiate a POP?
• Day 1 up to and including day 5 of menstrual cycle
• No additional contraceptive protection required.
• Ideally start on day 1 of menstrual cycle
• Day 6 of menstrual cycle onwards
• Additional precautions required, condoms or absitinence is
required for 2 days
• Postpartum
• up to and including day 21 postpartum. – no additional
contraception required
• Termination/Miscarriage
• Start immediately or up to 5 days after – no additional
contraception required
what is the missed pill guidance for POP if less than 3 hours late?-desogestrel
• Take the late or missed pill as soon as possible. • Continue taking the remaining pills at the usual time (even if it means taking two pills on the same day). • No additional contraceptive protection is needed.
what is the missed pill rule for POP if it is more than 3 hours late?
• Take the most recent missed pill as soon as possible (any other missed pills should be discarded). • Continue taking the remaining pills at the usual time (even if it means taking two pills on the same day). • Use additional contraception (or abstain until pills have been taken for 2 consecutive days. • Considder EHC if sexual intercourse within 2 days of missed pill
what are the disadvantages of POP’s?
high failure rate • It does not control the menstrual cycle as effectively as the COC pill. • Menstrual irregularities are common but tend to resolve with time • Small increased risk of breast cancer inc risk of ovarian cysts unscheduled bleeding
what is the general rule for unscheduled bleeding for POP?
- 2 in 10 women will become amenorrhoeic.
- 4 in 10 women will have regular bleeding.
- 4 in 10 women will have irregular bleeding.
what is categoyr 4 c/i for POP?
breast cancer
what is category 3 for POPs?- risk factor
• Past history of breast cancer.
• Severe cirrhosis.
• Liver tumours.
• Stroke and coronary heart disease (UKMEC 3 for continuation, 2 for
initiation).
• Systemic lupus erythematosus (SLE) with positive antiphospholipid
antibodies.
• Those on medication, including antiretroviral therapy, enzyme-inducing
anticonvulsants (not including lamotrigine and enzyme-inducing antibiotics
such as rifampicin and rifabutin
what are the interactions that involve POP?
• Enzyme inducing drugs (as per COC) reduce effectiveness of POP’s
• Contraceptive cover can be lost
• Not effected by non-enzyme inducing antibiotics e.g. Amoxicillin,
doxycycline
what guidance should be followed for drug interactions for POPs?
Short-term treatment (<2 months):
• Advise her to stop the POP and change to an alternative contraceptive
method
• or continue the POP but avoid sexual intercourse or use a barrier
method of contraception (such as condoms) while taking, and for 28
days after stopping.
Long term treatment (>2 months)
• Advise her to change to an alternative contraceptive method
unaffected by enzyme-inducing drugs i.e barrier methods or the
progestogen-only injectable).
what is the rule with vomiting and diarrhoea with POPs?
• Absorption of the oral contraceptives can be affected!
• If vomiting occurs (for any reason) within 2 hours of taking a pill then
take another pill ASAP.
• If the subsequent pill is taken more than 3 hours late (or 12 hours
for a desogestrel pill), she should follow the missed pill rules
• If vomiting or severe diarrhoea occurs for >24 hours advise:
• To follow the instructions for missed pills, counting each day of
vomiting and/or diarrhoea as a missed pill.
• To avoid sexual intercourse or use a barrier method of
contraception (such as condoms) during the illness interval and for
2 days afterwards
what are the POP availible OTC?
- Hana
- Licensed for women of childbearing age.
- £9.95 for a one-month pack and £21.95 for a three-month pack,
- Lovima
- Licensed for women of childbearing age including adolescents.
- £14.99 for a one-month pack and £29.99 for a three-month pack.
how much can you supply OTC?
- First supply — up to 3 months could be supplied
- Repeat supply — up to 12 months could be supplied
- Women under the age of 18 maximum 3 months could be supplied
what is the guidance when switching from COC to POP?
• Ideally complete the COC pill pack omitting the HFI • Start the POP the next day on from the last COC pill. (i.e day 22) • No additional contraception is required.
what is the guidance when switchin from the POP to COC?
Start the COC at any time in the menstrual
cycle
Traditional POP-
• Start the COC the next day after the
traditional POP.
• However, need to avoid sexual intercourse
or use a barrier method for the first 7 days
(9 days for Qlaira®).
Desogestrel
• Start the COC the next day after the
desogestrel POP
• No additional contraception is required
what is LARCS?
Long acting reversible contraceptives
give examples of LACRS?
Progestogen-only Injectable Contraception
Progestogen-only implant
Progestogen-only intrauterine systems (IUS)
Copper intrauterine device (Cu-IUD)
how does the progestogen-only injectable work?
- Medroxyprogesterone acetate
- Primarily by preventing ovulation
- Adminstered every 12 weeks for Depo-Provera® - I.M of DMPA
is the injectable affected by antibiotics/ liver enzyme inducing drugs?
no
what is in the progestogen-only implant?
- Etonogestrel (Nexplanon® implant)
* Protection lasts 3 years
is irregular bleeding common in the progestogen-only implant?
Irregular bleeding is common. 20% of women have amenorrhoea, and
almost 50% have infrequent or prolonged bleeding; bleeding patterns
likely to remain irregular but dysmenorrhoea may improve
how does IUS work?
• Levonogestrel intrauterine system (LNG-US)
• Release LNG directly into the uterine cavity
• Preventing endometrial proliferation, thickening of cervical
mucus, and suppressing ovulation in some women
how does the copper IUD work?
Non-hormonal intrauterine device containing copper
• Inhibits fertilization by copper’s toxic effect on sperm and ova
• inhibits implantation due to local endometrial inflammatory
reaction
