3. Contraception Flashcards
(31 cards)
Fraser guidelines for prescribing contraceptives to under 16’s
- She understands the doctor’s advice
- She cannot be persuaded to inform her parents
- She is very likely to continue having sex
- Her mental and physical health will suffer without contraception
- In her best interests to provide treatment
Types of combined -contraception
ORAL
* oestrogen (ethinylesteradiol, estradiol ect) AND progestogen (desogestrel, noresthisterone, levonorgestrel, nomegestrel)
TRANSDERMAL PATCH
* Evra patches (norelgestromin with ethinylestradiol)
VAGINAL RING
* Nuva ring (etongestrel with ethinylestradiol)
-strel = progestogen
Types of progestogren only contraceptives
ORAL
* desogestrel
* norethisterone
* levonorgestrel
PARENTERAL
* medroxyprogesterone (injection)
* Noresthisterone (injection)
* Etonogestrel (implant)
INTRAUTERINE DEVICE
* Levonorgestrel
Combined oral contraceptives mechansim of action
Inhibit ovulation
Combined oral contraceptives dosing and counselling
A menstrual bleed is caused by the shedding of the uterine lining as the uterine lining remains thin in females take COC, the patient’s menstrual period will not occur.
Take one tablet daily for 3 weeks + 1 week pill-free interval for withdrawal bleeding.
withdrawl bleeding is not a real period, the bleeding is induced by the drop in progestogen
Can begin anytime in menstrual cycle, if started on day 6 or after, use protection for 7 days.
Cannot be used by women older than 50 years, due to the increased risk of VTE.
Types of COC preparations
- Monophasic (fixed amount of oestrogen and progestogen)
- Phasic (varying amount of oestrogen and progestogen to mimic a normal menstrual cycle ). For women who do not have withdrawal bleeds or have breakthrough bleeds with monophasic preparations
- Every day prepation (pill-fre days replaced with inactive pills)
4.Low-stregnth oestrogen preparations (~20mg ethinylestradiol)
Used in women with a risk factor for circulatory disease, as they are at greater risk of VTE
COC risks
Risk of VTE
factors that increase risk further
* Obesity: BMI > 30
* Smoking
* Primary relative under 45 with VTE
* Immobilisation
* Age >35 years
* Type of progestofen: desogestrel, gestodene, drosperinone
Risk of arterial thromboembolism
factors that increase risk further
* diabetes mellitus
* hypertension
* migraine without aura
AVOID COC if 2 more mORE RISK FACTORS PRESENT
Combined oral contraceptives and surgery
Combined oral contraceptives should be stopped 4 weeks before major elective surgery.
For surgery to the legs or surgery that results in prolonged lower limb immobilisation:
- can switch to progestogen-only contraceptives as it is the oestrogen content that increases risk of VTE
- restart contraceptives on the first menses, at least 2 weeks following full mobilization
If surgery was not planned
- thromboprophylaxis with heparin and graduated compression hoisery can be used
These restrictions do not apply to minor surger with short duration anasthesia, e.g tooth extraction.
Also does not apply to women on oestrogen-free contraceptives
Combined oral contraceptives and travel
Can reduce risk of VTE with compression stocking and leg exercises
Signs of VTE
- Sudden severe chest pain, breathlessness, cough with blood-stained sputum PULMONARY EMBOLISM
- Unexplained swelling or severe pain in calf of one leg DEEP VEIN THROMBOSIS
- Serious neurological effects such as severe polonged headache, slurred speech, dysphagia, motor disturbances STROKE
The oestrogen component of combined oral contraceptives is responsible f
Combined oral contraceptives and oestrogen containing HRT risks
COC’s and oestrogen containing HRT occasionally cause liver dysfunction (jaundice, hepatitis, liver enlargement)
COC’s and oestrogen containing HRT may also cause an increase in blood pressure. SHOULD BE STOPPED if systolic goes above 160mmHg or disastolic goes above 95mmHg
Also increase the risk of breast and cervical cancer. BUT decrease risk of ovarian, colorectal and endometrial cancer.
Also reduce dysmennorrhea, menorrhagia, symptomatic fibroids and cysts
Combined oral contraceptives contraindications
Combined oral contraceptives should be stopped if a patient has a risk factor that contraindicates treatment:
- Smoking > 40 cigarettes
- History of arterial or venous thrombus
- Migraine/severe migraine lasting >72 hrs, migraine treated with ergot derivatives
- Diabetes mellitus with complications
- BMI >35
- Over 50 years
- Transient iscaemic attack
- Hypertension; systolic >160mmHg and diastolic >95mmHg
Progestogen-only pill (POP) mechanism of action
Prevents pregnancy by thickening the mucus in the cervix to stop sperm reaching an egg
Menstrual irregularities, heavy or light periods is common
Progestogen-only pill (POP) dosing regimen
One tablet is taken daily on a continuous basis, starting on day 1 and taken at the same time each day .
If the regimen is started after day 5 of the menstrual cycle, additional precuation must be used for 2 days, such as a condom
Progestogen-only pill (POP) risks
Increase the risk of breast cancer
Missed pill rules (COC)
If pill is missed for ≥ 24 hours
(Zoely/Qlaira ≥ 12 hours)
If its only 1 pill:
Take the missed pill AND take the next one at normal time even if it means taking two together. No more precautions needed for this.
If its 2 or more pissed pills:
Take one pill ASAP + condom for 7 days
(condom for 9 days if Zoely/Qlaira)
Miss out-pill free interval, if a pill is missed in the last 7 days of the cycle
If the pill is missed in the first 7 days and unprotected sex has occured - get EMERGENCY HORMONAL CONTRACEPTION
Progestogen-only pill (POP) missed pill rules
If pill is missed for > 3 hours
(Desogestrel > 12 hours)
Take ASAP + use condom for 2 days
If a woman has missed 1 or more pills and has had unprotected sex, before 2 pills are taken correctly = Obatin emergency hormonal contraception
Combined oral contraceptives (COC) - vomiting/diarrhoea
If vomiting/diarrhoea occurs less than 2 hours of taking it - TAKE ANOTHER ONE
In more serious cases of vomiting/diarrhoea lasting >24 hours - additional protection must be used during and 7 days (9 days if Qlaira) after recovery. Pill can then be resumed.
If vomiting/diarrhoea occurs in the last 7 days - pill-free interval must be missed out
Progestogen-only pill (POP) - vomiting/diarrhoea rules
If vomiting/diarrhoea occurs less than 2 hours of taking it - TAKE ANOTHER ONE
If vomiting/diarrhoea is severe or pill is not taken within 3 hours of normal times (12 hours if desogestrel) - additional protection must be used during and 2 days after recovery and pill is resumed
Transdermal patch (Evra) application/dosing
1 weekly patch is applied for 3 weeks, then 1 week is patch freee
If a patch is detached for less than 24 hours
* it can be attached or replaced immediately. No additional protection is needed.
If a patch is detached for >24 hours or application is delayed at the start of the cycle:
* the current contraceptive cycle should be stopped and a new patch should be applied + condom should be used for 7 days
If a women forgets to apply her patch in the middle of the cycle (beginning of week 2 or week 3)/day 8 or 15:
* If it has been ≤48 hours - a new patch can be applied immediately and can be continued as normal.
* If it has been > 48 hours - a new contraceptive cycle must be started + condom for 7 days
Contraceptives interactions
Exceptions to these contraceptive interactions include IUD’s and progestogen only injections BUT include emergency hormonal contraceptives
The effecriveness of contraceptives can be reduced by hepatic enzyme inducing drugs
* CRAPGPSSS
Alterntaively, if contraception cannot be changed or stopped
* IUD OR Progestogen-only injections can be used
Emergency contraception alternative methods
Ulipristal efficacy is reduced by drugs that increase gastric PH, like antacids, H2 receptor antagonists, PPI’s
* copper IUD
* 3mg dose of levorgestrel (unlicensed)
C CARBAMAZEPINES
R RIFAMPICIN
A ALCOHOL
P PHENYTOIN
G GRISEOFULVIN
P PHE
Emergency contraceptive options
1st line: Copper IUD
Most effective
Inserted up to 5 days after unprotected intercourse or up to 5 days after the earliest calculated ovulation
Intrauterine devices are unsutiable for women <35 years as they are at increased risk of pelvic inflammatory disease
2nd line: hormonal methods
Oral EHC: levonorgestrel or ulipristal (more effective)
If BMI>26kg/m2 or >70kg: ulipristal or double dose of levonorgestrel
Levonorgestrel mechanism of action and dose
Mechanism of action:
prevents ovulation and fertilisation
Dose:
1500mg < 72 hours (3 days) of unprotected sex
If vomiting occurs within 3 hours of taking the dose, must have a replacement dose.
Caution:
* Crohn’s disease
* Past ectopic pregnancy
* Ciclosporin (due to toxicity)
Ulipristal mechanism of action, dose, cautions and contra-indications
mechanism of action: progestogen receptor modulator inhibits or delays ovulation
dose: 30mg must be given within 120 hours (5 days) of unprotected sex.
If vomiting occurs less than 3 hours of taking dose, provide replacement dose
caution:
* severe asthma treated by oral corticosteroids
* severe liver impairement (AVOIDED)
contraindications:
- repeated use within same menstrual cycle (only levonorgestrel can be used repeatedly within the same menstrual cycle)
