Contraception Flashcards
What is Contraception?
- Intentional prevention of pregnancy by artificial or natural means
What are the Reasons for Contraception?
- Gives women the ability and choice on when to start a family
- Cost-effective health-care interventions
- Population control
What are the Factors Influencing Contraceptive Choice?
- Cultural, religious and personal beliefs
- Side effects/contraindications
- Previous experience/use
- Access to health care
- Understanding of effectiveness
- Need for STI prevention
- Cost associated
- Preference for permanent or temporary contraception
List 3 Barrier Methods
- Male condoms
- Female (internal) condoms
- Diaphragm
What is the role of Male Condoms?
- Prevent the transfer of genital fluids between partners and reduce risk of STI
What are the Benefits of Male Condoms?
- Good efficacy
- Readily available, no prescription
- Reduce risk of STIs
- Available in formulations suitable for latex allergies
- Can be used with water based lubricants
What are the Disadvantages of Male Condoms?
- Condoms can break/tear or slip off
- Oil based lubricants can damage latex and cause a tear
- Compliance
What are Female (Internal) Condoms?
- Inserted into the vagina before sex
- Reduces STI risk
- Female required to practice insertion before use and insert 6 hours prior
- Not readily available
What is a Diaphragm?
- Inserted into the vagina and covers the cervix
What does the COCP contain?
Contain an estrogen and progestogen in various formulations and strengths
COCP: What is the role of Estrogen Component?
- Estrogens suppress the FSH release from the pituitary
- Prevents follicle development
COCP: What is the role of Progesterone Component?
- Can inhibit ovulation by blocking LH surge
- Increase the thickness of cervical mucus
COCP: What is the role of the combination of Estrogen and Progesterone?
- Alter endometrium to discourage implantation
What is the goal of the COCP?
- The goal is to use the lowest dose of estrogen and progestogen whilst achieving:
- Effective contraception
- Cycle control
- Minimal adverse effects
- Non-contraceptive benefits e.g. acne
What is Monophasic?
- Same amount of estrogen and progestogen in each active pill
What is Multiphasic?
Slow increase in estrogen and potentially progestogen – aim is to mimic the natural cycle
What are the three types of synthetic estrogens available in the COCP?
- Ethinylestradiol
- Estradiol
- Mestranol
What type of Progesterone is used in the COCP?
- Rapidly metabolised in the liver
- Synthetic progestogens are used in the COCP to ensure efficacy
- Newer generations of progesterone have fewer side effects as they bind more selectively to the progesterone receptor
What is Extended Cycling?
- Women continue to take the active pill
- Bicycling and tricycling
- Avoid withdrawal bleed
- Can improve compliance
- It’s recommended that a withdrawal bleed occurs at least every 3-4 months
What are the Benefits of COCP other than contraception?
- Reduce the chance of endometrium, ovarian and bowel cancers
- Be used as a treatment for pre-menstrual syndrome (PMS)
- Improve acne and hirsutism
- Regulation of menstrual bleeds in regards to timing and reduced volume
- Can time withdrawal bleed
- Easily reversible and has no effect on future fertility
What are Contraindications of COCP?
- Cardiovascular:
- Hx of cerebrovascular event or coronary artery disease, VTE or thrombogenic mutations
- All CV risk factors need to be assessed prior to COCP being prescribed
- Breast cancer
- Migraine with aura
What are Precautions to look out for in COCP?
- Unexplained vaginal bleeding
- COCPs can exacerbate or relieve migraine
- Smoking increases risk of thromboembolism and CV event
- < 35 years can use
- > 35 years contraindicated
- Age
- > 40 years increased risk of CVD and VTE
- Can be used until age 50 if no other CV risk factors
- BMI > 39
- Risk of thromboembolism increases with increasing BMI
- Malabsorption syndromes
- Systemic lupus erythematosus
- Antiphospholipid syndrome – avoid use, risk of thrombosis increased
- Hereditary angioedema – exacerbated by COCPs
- Hepatic – CI when liver function compromised
- Surgery increases risk of VTE
- Elective surgery – hold 4 weeks pre-operatively
- Pregnancy
- No increased risk of birth defects
- Postpartum
- Increased risk of VTE
- Breastfeeding
- Estrogens may decrease milk
What are Adverse Effects of COCP?
- Nausea
- Breast tenderness
- Bloating and fluid retention
- Headache
- Dysmenorrhoea
- Decreased libido
- Breakthrough bleeding
- May potentially increase risk of first time depression
Most estrogens and progestogens are metabolised by what?
CYP3A4
CYP3A4 inducers can what?
Reduce contraceptive efficacy
What are examples of CYP3A4 inducers?
- Carbamazepine
- Phenytoin
- Rifamycins except rifaximin
- St John’s Wort
What are Alternate options for contraception when there are drug interactions?
- Levonorgestrel or copper IUD
- Medroxyprogesterone depot
If it’s not possible to change type of contraception and also taking a CYP3A4 inducer, the following should be considered:
- Monophasic COCP with levonorgestrel with ethinylestradiol
- Ethinylestradiol should be at least 50mcg daily
- 2 x COCP containing 30 mcg
- OR
- 1 x COCP 30mcg + 1 x COCP 20mcg
- Avoid Microgynon as progestogen dose insufficient
- Extended cycling with reduced hormone=free intervals
- Advise to use additional forms of contraception e.g. condom
Discuss the Interaction between Lamotrigine and COCP?
- COCPs can increase lamotrigine’s metabolism, decrease in efficacy
- Lamotrigine concentration may not be affected if patient also taking strong inducer (phenytoin) or inhibitor (valproate)
- If possible alternate contraception should be used
- May need to increase lamotrigine dose
Discuss abx interactions?
- If non-rifamycin: pill shouldn’t be affected
When should COCP be started: For immediate contraceptive protection?
- First active tablet must be taken within five days of onset of menstruation
When should COCP be started: After first five days of menstruation?
- Need seven consecutive active tablets to ensure that ovulation won’t occur
- 7 day rule
When should COCP be started: If switching from another COCP?
- Start taking active pills the day after stopping your previous COCP
When should COCP be started: If switching from a progestogen only pill (POP)?
- Start taking active pills the day after stopping your previous POP
- 7 day rule
What is the point of the 7 day rule?
- Use additional contraceptive protection for the 7 days
What is the 7 day rule based on?
- When you take the pill, it takes 7 days of active pills for it to be effective
- When you stop taking the pill, it takes 7 days for it to stop working
If the following occur, the pill may not be effective?
- Active pills are missed in the week before, or the week after taking the sugar pills
- The sugar pill interval extends beyond 7 days
- Two or more active pills are missed i.e. more than 48 hrs since last pill taken
- Vomiting occurs within 2 hours of taking the pill
- Severe diarrhoea
- Interactions with other medicines
What’s considered a missed pill?
- < 24 hours that they missed pill i.e. an active pill was taken within the last 48 hours
- > 24 hours that they missed pill i.e. an active pill hasn’t been taken in the last 48 hours
- < 24 hours that they missed pill i.e. an active pill was taken within the last 48 hours
- Take the missed pill as soon as you remember then continue on with next pill at usual timing, contraception won’t be affected
- > 24 hours that they missed pill i.e. an active pill hasn’t been taken in the last 48 hours
- Take active pill as soon as you remember, contraception may be affected
- Other forms of contraception will be needed until 7 consecutive days of active pill have been take
What’s Considered a Missed Pill?
Prior to forgetting to take the pill, the active pill was taken 7 consecutive days in a row and there are 7 consecutive active pills to take
What do you do?
Continue taking active pills
What’s Considered a Missed Pill?
7 consecutive active pills haven’t been taken prior to the missed pill
What do you do?
Emergency contraception may be indicated
What’s Considered a Missed Pill?
Missing a pill in the third week of active pills
What do you do?
Inactive pills need to be skipped to ensure 7 consecutive active pills are taken
What’s Considered a Missed Pill?
Patient has missed an inactive pill
What do you do?
Advise patient to continue taking pills as per normal pill packet
What is the Role of Progestogen Only Methods?
What are the Mechanisms of Action?
- Don’t consistently inhibit ovulation
- Mechanism of Action:
- Increases the thickness of cervical mucus
- Decreases sperm motility
- Slowing ovum movement
- Inhibition of uterine lining development
- Reduction of cilia activity in the fallopian tube
Progestogen Only Pill
What does it contain?
What are the Side effects?
Does it need to be taken at the same time each day?
When is it useful for?
- ‘Minipill’ containing either levonorgestrel or norethisterone with no sugar pills
- Side effects: spotting, irregular periods, heavy periods, absent periods
- Take at the same time each day
- If dose is delayed by >3 hours, contraceptive failure is possible
- Effective in 48 hours
- Useful when COCP isn’t appropriate e.g. breastfeeding
Medroxyprogesterone Injections
- Intramuscular injection every 12 weeks
- Delay in the return to normal cycles for 6 months or longer after stopping
- Increased risk of osteoporosis in older women and in adolescents
Intra-Uterine Devices
- Inserted by medical professional
- Hormonal IUD
- Levonorgestrel (Mirena) IUD
- Needs to be replaced every 5 years
- Very effective
- Not suitable for women with past or current breast cancer
- Can cause irregular bleeding/spotting
- Many women have no periods
- Copper IUD
- Not suitable for woman who experience painful and long periods, copper allergy, anaemia
- Needs to be replaced every 10 years
- Can be used for emergency contraception
- Fertility returns when IUD removed
Contraceptive Vaginal Ring
- Nuvaring = combination of ethinylestradiol and etonogestrel
- 3 weeks in, 1 week out
- Need to learn how to self insert
- Risks similar to COCP
- Additional risk of device expulsion
- Expulsion for 3 hours may lead to inefficacy
What is Emergency Contraception Indicated for?
- Indicated for unprotected sex or contraceptive failure
What do hormonal emergency contraception pills delay?
Ovulation
Emergency Contraception: Levonorgestrel Pill
When’s the best time to take it?
Are there drug interactions?
What are the Side Effects?
When should further action be taken?
- Best taken with 72 hours after unprotected sex
- For use up to 96 – 120 hours after unprotected sex, efficacy uncertain after 72 hours
- If > 72 hours, used other forms of EC if possible
- Drug interactions with CYP3A4 inducers
- Side effects:
- Nausea, vomiting, vaginal bleeding, next period may be slightly late or early
- If next period is > 1 week late, light or unusual, a pregnancy test is indicated
- If next period doesn’t occur within 3 weeks, customer needs specialist advice
Emergency Contraception: Ulipristal Pill
What is it licensed for use up to?
What are the Side Effects?
How long does the patient need to wait before taking hormonal contraception again?
Drug interactions?
When should further action be taken?
- Licensed for used up to 120 hours (5 days) after unprotected sex
- Side effects:
- Nausea, vomiting, vaginal bleeding, next period may be slightly late or early
- The customer needs to wait 5 days before taking hormonal contraception again
- Advice on additional contraception during this time and for the additional 7 days for COCP to be effective
- Drug interactions: Ulipristal is a CYP3A4 substrate
- If next period is > 1 week late, light or unusual, a pregnancy test is indicated
Emergency Contraception: Copper IUD
- Requires customer to have access to medical facility for insertion
- 99% effective if inserted within 5 days of unprotected sex
What other considerations need to be considered in terms of Emergency Contraception?
- Consider STI risk
- Timing matters
- If unprotected sex occurred > 120 hours ago = referral
