Non-LARC contraceptives Flashcards
What three methods are included in combined hormonal contraceptive?
- COCP
- Combined transdermal patch (CTP)
- Combined vaginal ring
CHC:
- what is the primary mode of action?
- what other effects does it have on the uterus?
- what is the failure rate of COCP?
- what could affect the effectiveness of CHC?
Mode of action:
- Primary = Inhibiting ovulation via action on hypothalmic-pituitary-ovarian axis to reduce luteinising and follicle-stimulating hormones
- Also = Alters cervical mucous and renders endometrium unfavourable for implantation
Failure rate:
- perfect use = 0.3%
- typical use = 9%
Factors that affect effectiveness:
- Impaired absorption: GI conditions (COC)
- Increased metabolism: Liver enzyme induction,Drug interaction (rifampicin/some antiepileptics/st johns wort/some antiretrovirals)
- Forgetting
- Describe the standard regime of COCP
- describe tailored regimes that are used off licence?
- what factors may affect effectiveness of COCP?
- What happens if one pill is missed?
- what happens if 2 pills are missed?
Standard regime:
- Take daily for 21 days then stop for 7 days during which a withdrawal bleed occurs due to shedding of the endometrium
- The first 7 pills taken inhibit ovulation and the remaining 14 pills in the pack maintain anovulation
- Follicular activity may resume after 9 pills have been omitted
Tailored ‘off-licence’ regimes:
- Tri-cycling – 3 ‘packs’ taken back to back then 7 days off
- Shortened hormone free interval – 3 weeks of CHC use then 4 days off
- Extended use – method used continuously until breakthrough bleeding occurs then stop for 4 or 7 days
If one pill is missed/started pack 1 day late (over 24 hours and less than 48hours):
- take last pill missed now
- continue taking pack as usual
- EC not needed
If two or more pills are missed (over 48 hours)/started pack 2 days late:
- take last pill missed now (leave any earlier missed pills)
- continue taking rest of pills
- additional contraception for next seven days
- if UPSI in the previous 7 days and on day 1-7 need EC, if on day 8-14 doesn’t need EC, if on days 15-21 omit break
- if 7 or more pills left in pack have usual seven day break
- if less than 7 pills left in pack miss out break
What is the standard treatment regime of CTP?
- How long can the patch remain off before efficacy is reduced?
- how long can the patch be worn before the efficacy is worn off?
- how long can the patch free break be before efficacy is reduced?
Standard regime:
-One patch is applied and worn for 1 week to suppress ovulation. Thereafter the patch is reapplied weekly for a further 2 weeks. The fourth week is patch-free to allow a withdrawal bleed. A new patch is applied after 7 patch-free days
Removal of patch: can remain off up to 48 hours before efficacy is reduced*
Patch can be worn for up to 9 days (7 days +48 hours) before efficacy reduced*
Patch free interval can be extended up to 9 days (7 days + 48 hours) before efficacy reduced*
- What is the standard regime for combined vaginal ring?
- How long can ring be left out of vagina before efficacy is reduced?
- How long can a ring be worn without efficacy being reduced?
- How long can a ring free interval be extended by without efficacy being reduced?
standard regime:
-ring placed around cervix for 21 days and then ring free interval for 7 days
Ring can be left out of vagina for up to 48 hours before efficacy is reduced
Ring can be worn for up to 4 weeks without efficacy being reduced
Ring free interval can be extended by 48 hours without efficacy being reduced
CHC:
-what does it increase the risk of?
VTE - in those with other risk factors for VTE
Systemic hypertension - check initially, then at 3 mths, then annually
Stroke/MI - in hypertensive (systolic 160 or more, diastolic 95 or less), contraindicated in migraine with aura
Age>35 UKMEC 2 (benefits outweigh risks but consider other risks)
Breast cancer:
- personal history = CHC contraindicated
- FH = UKMEC 1
- BRACA = UKMEC 3
Cervical cancer - slightly increased risk so smears
Breast feeding 0-6wks UKMEC 4
what are the risk factors for VTE?
Obesity Smoking Age Known thrombophilia VTE in first degree relative < 45 yrs Up to 6 weeks postnatal Trekking > 4,500 m for > 1 week Long-haul flights Reduced mobility Antiphospholipid syndrome Other conditions causing increased VTE risk
What does CHC protect against?
20% reduction in ovarian cancer for every 5 years of use to a maximum 50% reduction after 15 years use
20% - 50% reduction in endometrial cancer
The benefit for both may last decades after stopping CHC
Good for ACNE (dianette)
What is diannette made up of?
Co-cyprindiol
Acne and hirsutism treatment
Ethinyl-estradiol 35μg/cyproterone acetate 2 mg
What are the side effects of CHC?
Unscheduled bleeding – up to 20% experience, usually settles with time. Don’t change before 3 months
Mood changes – can occur but no evidence it causes depression
Weight gain (Cochrane 2013) – insufficient evidence but no big effect. Need studies with dummy pill/non-users to show weight change with time
CTP – more breast pain, nausea, painful periods than COC/CVR
CVR – less bleeding problems, acne, irritability/mood changes
Starting CHC:
-when can you start a CHC?
Standard Advice – COC’s can be started up to and including Day 5 of the cycle without the need for any additional contraception
Beyond Day 5 a woman can start the COC at any other time (off licence) provided she is ‘reasonably certain’ she is not pregnant and use condoms/abstinence for 7 days – ‘quick start’
Emergency contraception:
- Levonelle 1500 (progestogen) – abstain/condoms 7 days
- Ulipristal Acetate (anti-progesterone) - hormonal contraception interferes with action of Ulipristal Acetate so avoid starting contraception for 5 days
If amenorrhoeic
if post-partum and not breast feeding
post TOP
Progesterone only pills:
- what types exist?
- what is the mode of action?
- risks of POP
- interactions of POP?
Includes:
- ‘traditional’ POPs – levonorgestrel, norethisterone
- Newer POP – etonorgestrel - longer acting
Mode of action:
Primary mechanism: Thickening of cervical mucous, Etonorgestrel – suppression of ovulation in up to 97% of cycles
Secondary:
- Suppression of ovulation in up to 60% of cycles (Levonorgestrel)
- decrease endometrial receptivity to blastocyst
- Reduction in cilia activity in fallopian tube
Risks:
UKMEC4 if current breast cancer
Interaction with liver enzyme inducers - Cytochrome P450:
- Suitable alternative - DMPA, IUS, Cu-IUD
- Effect continues for 28 days after stopping
What is the treatment regime for progesterone only pills?
What is to be done if 1 pill is missed?
What is he failure rate?
‘older’ pills – levonorgestrel, norethisterone
Daily at same time
No break
Within 24 - 27 hours of last dose
Etonorgestrel
Daily at same time within 24 – 36 hours of last dose
No break
One missed dose plus UPSI
= emergency contraception plus 2 days extra protection
Efficacy: Perfect use 0.3% failure Typical use 9% failure Etonorgestrel – theoretically more effective. Age important
