TBL contraception Flashcards
What are the different types of progesterone that can be used in the contraceptive pill?
They are either 2nd generation progesterone which includes:
Levonorgesterol
Norethisterone
Norgestimate
3rd generation progesterones:
Desogesterol
Gestodene
4th generation progesterone:
Drospirenone
What is an appropriate dose of oestrogen to be found in combined contraceptive pills?
Either low dose 20mcg or standard dose 30-35mcg, no higher is given due to risk of thromboembolism
What is an example of a monophasic, biphasic or triphasic combined oral contraceptive?
Monophasic: Microgyon
Biphasic: Azurette
Triphasic: Trivora
Explain the principle of a monophasic combined pill?
It contains the same amount of oestrogen and progesterone in every single pill in the cycle and is prepared in 21 day or 28 day formulations.
Explain the principle of a biphasic combined pill?
They use a lower ratio of oestrogen: progesterone in the first half of the cycle and then a higher ratio in the second to mimic the natural levels during the menstrual cycle.
Explain the principle of a triphasic combined pill?
The combination of hormones changes approximately every week during the pill cycle, providing three phases.
Why would you chose biphasic or triphasic over a monophasic preparation?
Patients medical history
Personal preference
Previous contraceptive experience
Age related considerations
What are some of the advantages of the combined oral contraceptive pill?
Reduces menstrual pain and bleeding
Reduces risk of ovarian, endometrial and colorectal cancer
Predictable bleeding pattern
Maintains mineral bone density of pre-menopausal women under 50
Protects against pelvic inflammatory disease
What are some of the disadvantages of using the combined contraceptive pill?
No protection against STIs
Increased risk of breast cancer
Increased risk of ovarian cancer
Causes fluid retention so can lead to an increase in weight
Acne
Risk of venous thromboembolism
Breast tenderness
Mood swings
Increased risk of stroke
Breakthrough bleeding
What are the other four risk factors for developing deep vein thrombosis that are contra-indicated in use for combined oral contracpetives?
Family history (first degree relative who developed one under 55)
Surgery
Long haul flight
Obesity
When is combined oral contraceptives contra-indicated?
2 or more risk factors of DVT
Active liver disease
Breast feeding
Major surgery
Current or past history of VTE, stroke or ischaemic heart disease
How long in advance should you stop COC before surgery and restart after surgery?
4 weeks in advance due to risk of DVT and continue at first menses at least 2 weeks after full mobilization is regained.
Which surgery should you stop COC?
Any surgery to the legs or surgery that is going to cause immobilisation
If surgery is an emergency, what is the appropriate steps to implement to avoid DVT?
Compression hosiery and prescribe thrombo-prophylaxis (heparin)
What are some of the risk factors of DVT?
FH of VTE/arterial disease in first degree relative <45yrs
▪ Obesity – BMI > 30 (avoid if BMI >35)
▪ Long term immobilisation
▪ >35 yrs (avoid if >50 yrs)
▪ Smoking
▪ DM (avoid if diabetes complications)
▪ HT - >140/90 (avoid if >160/95)
▪ Migraine without aura (avoid if migraine with aura)
What are some of the benefits of the progesterone only pill?
Reliable and reversible
Does not have the oestrogen associated risks
Can use whilst breast feeding
Can be used in patients where the combined pill is contraindicated
Which patients are suitable for the progesterone only pill that can’t take the combined pill?
Heavy smokers (over 15 a day)
Over 35
Hypertension
Diabetes
Migraine
Major surgery
What are some of the disadvantages of the progesterone only pill?
Must be taken at the same time each day (three hours later than the normal dose means you are not protected).
Increases risk of ovarian cysts
Increases risk of breast cancer
Can cause menstrual irregularities
No STI protection
Do you have to alter progesterone only contraception before surgery?
No it does not need to be changed as it does not cause an increased risk of DVT.
What should you do if a women misses one or pill or starts the pack one day late on both the combined pill or the progesterone only pill?
Combined pill: Missing one pill
Take the pill immediately even if it means taking two pills in one day.
Carry on as normal
You are still protected
Combined pill: Starting the pack a day late
Same advice as above, on starting the medication if you take your first pill more than five days after the start of your period you are not protected and need to use additional methods of contraception for 7 days.
Progesterone only: Missing one pill
If you are less than 3 hours late for a traditional POP Noriday, Micronor, Norgeston
If you are less than 12 hours later for a desorgesterol containing pill such as Cerelle or Cerazette
You are protected and just take the pill immediately even if it means taking two in one day and then carry on as normal
More than 3 or 12 hours, same advice as above but you are not protected and need to use extra protection for two days.
What should you do for the combined contraceptive pill if you miss more than 2 pills?
If you are in Week 1 of your pill cycle (pills 1-7)
Probably unprotected.
Take the last missed pill immediately and leaving the missed pills before and carry on as normal.
Will need to use additional contraception for the next 7 days.
Will need emergency contraception if you have unprotected sex in the 7 days after missing.
Still have pill break
Week 2: (pills 8-14 days)
Take the last missed pill immediately and leaving the missed pills before and carry on as normal.
Will need to use additional contraception for the next 7 days.
Do not need emergency contraception
Still have a pill break
Week 3: (pills 15-21 days)
Take the last missed pill immediately and leaving the missed pills before and carry on as normal.
Will need to use additional contraception for the next 7 days.
Do not need emergency contraception
If your pack usually has 21 pills in it, take the rest of the pills in your pack as normal and start a new pack the next day.
If your pack usually has 28 pills in it, take the rest of the active pills (the first 21 pills in the pack) as usual. When you have taken the last of the active pills, start a new pack the next day.
Do not have a pill break
What should you do if you are sick or have diarrhea with the contraceptive pill?
If you are sick or have diarrhea within 3 hours for the combined contraceptive pill or 2 hours for the progesterone only, you need to:
Take another pill
Carry on afterwards as normal taking your next pill at the normal time the following day
Do not need to use extra contraception for the following days or emergency contraception as long as your are not sick again.
If sickness carries on for more than 24 hours, count each sick day as a missed pill.
Which broad spectrum antibiotics interact with combined oral contraceptive?
Penicillin and tetracyclines
No longer need to use additional contraceptive methods whilst taking a course of antibiotics however GI disturbances of associated with the antibiotics may cause sickness/ diarrhea and therefore treat as appropriate.
Why can’t you take anti-epileptics with combined oral contraceptive?
They reduce the levels of progesterone and oestrogen
What are the options if you take anti-epileptic drugs?
Switch type of contraception to either the IUD or progesterone injection
Short term:
3packets of 30mcg monophasic
combined without a break followed by a short tablet-free 4 days plus CONDOMS
Short and long term:
‘Double dose’ (unlicensed) – take two pills daily to give at least
50mcg under ‘continuous’ or ‘tricycling’ regimen
Continue 28 days after stopping anti-epileptics
Which other drugs are enzyme inducers of the combined oral contraceptive pill?
Rifampicin and Rifabutin
St John’s Wort
Anti-retrovirals
Lamotrigne
What is the interaction with Lamotrigne?
Loss of seizure control and risk of toxicity in pill free period
Which type of drugs affect progesterone only pills?
Broad spectrum antibiotics do not impact the drug however enzyme inducers decrease the effectiveness and therefore you have to use additional methods of contraception until 28 days after.
What is the method of action of desogesterel?
Inhibits ovulation
What are the directions of application for a combined patch?
Apply a patch weekly for 3 weeks and then a 7-day patch free period. Should be placed on a dry, clean, hairless area such as the bum, upper torso (not breasts), arm or abdomen.
What is the formulation of the combined patch?
600mcg Ethinylestradiol + 6mg Norelgestromin
* Patch releasing:
▪ 20mcg/24hrs ethinylestradiol
▪ 150mcg/24hrs norelgestromin
What is the name of the combined patch?
Evra
What are some of the advantages of using a combined patch?
Do not have to worry about taking it everyday
Does not interfere with sex
Very easy to apply and only needs to be changed every week
Very effective
What are some of the disadvantages of using the combined patch?
Can cause local skin reactions
Does not protect against STIs
Visible
May not stick
Same risks and side effects as the combined pill
Not appropriate for women over 90kg
Withdrawal bleeding normally starts a day later than the combined pill and can carry over into the next cycle.
What should you do if the patch comes off up to 24 hours in the first week?
In the first week it is recommended to start a new cycle of patches and use additional methods of contraception for up to 7 days and emergency contraception if required.
How does advice change if you have the patch off for up to 48 hours in the second or third week?
You do not need any additional precautions or emergency contraception like the first week, you should start a new patch immediately and change the day of swap over for the next cycle of patches.
What happens if the patch is removed for over 48 hours for the second or third week?
Start a new 4 week patch cycle immediately and therefore will need additional contraception for the next 7 days and emergency contraception if required.
What happens if it is over 48 hours for the second or third week?
Start a new 4 week patch cycle immediately and therefore will need additional contraception for the next 7 days and emergency contraception if required.
Why is the ethinylestradiol dose for a transdermal patch higher than for a pill?
To compensate for the lower bioavailability in the trans-dermal route.
When is the steady state concentration reached for Evra patches?
Two weeks after the first application
What are the steady state concentrations of the two components of the combined patch?
0.305 – 1.53ng/ml for norelgestromin and 11.2 – 137 pg/ml for ethinylestradiol
What are the two components of the combined vaginal ring?
Etonogesterol and ethinylestradiol
What is the release rate of the etonogesterol?
15mcg/24 hours
What is the release rate of ethinylestradiol in the combined contraceptive pill?
120mcg/24 hours
What are the directions for the vaginal ring?
Insert one for three weeks and then remove for one week.
Before dispensing it should be stored within the fridge but is then okay to be stored for 4 months at room temperature.
What are the five advantages of using the vaginal ring?
Very effective
Only have to insert once a month
Immediate contraception if inserted on first day of menstrual bleed
Does not interfere with sex
Absorption not affected by D&V
What are the five disadvantages of using the vaginal ring?
Same risks as the implant or combined oral contraceptives
Can cause local reactions (vaginal dryness and irritation)
Risk of expulsion
No protection against STIs
Same drug interactions as the combined pill (possibly less as it passes first pass metabolism in the liver)
When should you discard a vaginal ring that has been expulsed?
If the patient is within a third week of their cycle and the vaginal ring has been expulsed longer than 3 hours, if this occurs within week 1 and 2 then it does not have to be discarded.
What are the two options you have if your vaginal ring has been expulsed more than 3 hours in week 3?
Discard and then either start a new ring beginning a new three week cycle or have a 7 days break and use additional contraception and then start again.
What should you do if expulsion of the vaginal ring occurs in weeks 1 or 2?
Wash and reinsert and then use additional contraception for the next 7 days.
What happens if expulsion is just under 3 hours?
Wash and reinsert and no further action is required.
What polymer is used in the extended release version of the vaginal ring?
Ethylene vinyl Acetate copolymers and is known as Evatane
What are the two components of a Nuvaring?
11.7 mg etonogestrel and 2.7 mg ethinyl
estradiol
Briefly describe how Nuvaring mechanism works?
Low concentrations of hormones are released continously and are rapidly absorbed into the vaginal mucosa throughout the three week cycle.
Why does the vaginal ring have less side effects than some of the other types of hormonal contraception?
Its route of administration avoids first pass metabolism and therefore has an increased bioavailability so can be used at lower concentrations to achieve an optimum plasma concentration, because of this there are then less side effects.
What is the hormone of Depo-provera?
Medroxyprogesterone acetate
How often is the Depo-provera injection administered?
150mg intramuscular injection every 12 weeks, used for both short and long-term contraception.
Aside from Depo-provera, what is the other type of progesterone only injection and when is it used?
Norethisterone enantate (Noristat)
This type of injection is only licensed for short-term use (maximum two injections, 200mg every 8 weeks)
What are some of the advantages of the injection? (4)
Effective and reversible
Does not interrupt sex
Convenient
Suitable for use before major surgery, surgery to legs or surgery which involves
long periods of immobilisation
What are some of the disadvantages of the injection?
Delay to return to fertility after use
Increases the risk of breast cancer
Decreases mineral bone density (risk of osteoporosis)
Must be done by a healthcare professional
Menstrual irregularities
Doesn’t protect against STIs
Same risks and complications associated with progesterone only pills
What should you do with a delayed injection?
For the depo-provera injection if the interval greater than 12 weeks and 5 days,
exclude pregnancy before next injection and additional precautions for 14 days
after injection.
Do broad spectrum antibiotics and an enzyme inducers interact with the progesterone only injection?
No there is no effect on its activity
What is the formulation of the depo-provera injection?
1mL intramuscular injection of 150mg/mL
What is the component of the contraceptive implant and what is its strength?
68mg Etonogestrol
How quickly after implantation does the implant protect?
Immediately after and is effective for three years
What are some of the advantages of the contraceptive implant?
Immediate protection
Does not interrupt sex
Very effective and rapidly reversible
Do not have to worry for three years
Can be used when breast feeding
Suitable for use before major surgery, surgery to legs or surgery which involves
long periods of immobilisation
What are some of the disadvantages of the implant?
Menstrual irregularities
Weight gain
Bruising at the site of administration
Must be done by a healthcare professional
Acne, breast pain, headache
Decrease in bone mineral density
No STI protection
Same risk factors as the progesterone only pill
Are there any drug interactions associated with the progesterone only implant?
Only enzyme inducers which reduce the effectiveness of the implant and alternatives should be used or use additional methods of contraception such as condoms for 28 days after
Describe the components of the contraceptive implant.
The core of the polymer is formulated with ethylene vinyl acetate, 68 mg of the
synthetic progestin etonogestrel, barium sulfate (radiopaque), magnesium
stearate, surrounded by an EVA copolymer skin.
What is the initial release rate of the contraceptive implant?
60-70 micrograms per day (Week 5/6)
How does the rate of release of the implant change from end of year 1 to 3?
35-45 micrograms per day and reduced to 25-30 micrograms a day.
What are some of the advantages of the intrauterine system?
Does not interrupt sex
Remains there for 5 years so does not have to be thought about daily
Periods become lighter and less painful
Convenient
Reversible
Effective as soon as inserted if put in during the first seven days of the cycle
Is the intrauterine system hormonal?
Yes it contains 52 mg levonorgestrel