Progesterone-Only Injection & Implant Flashcards
What is involved in the progesterone-only injection?
- a SC or IM injection is given every 12-13 weeks
- the injection contains medroxyprogesterone acetate
- it is also referred to as DMPA
How does medroxyprogesterone acetate affect return of fertility?
- it can take up to 12 months for fertility to return to normal after stopping the injection
- this makes it less suitable for women wishing to get pregnant in the near future
What are the 2 commonly used versions of the injection?
Depo-Provera:
- given as an intramuscular injection
Sayana Press:
- a subcutaneous injection that can be self-administered
they both contain medroxyprogesterone acetate
What is noristerat and when is it used?
- an alternative injection containing norethisterone
- it works for 8 weeks
- it is used as short-term interim contraception, such as after a partner has had a vasectomy
What are the UK MEC 4 criteria for using the injection?
active breast cancer
What are the UK MEC 3 criteria for using the injection?
- ischaemic heart disease / stroke
- severe liver cirrhosis / cancer
- unexplained vaginal bleeding
What must be considered in older women requesting the injection?
- it can cause osteoporosis
- this is significant in older women + patients on steroids for asthma / inflammatory conditions
- it is UK MEC 2 in women > 45 and they should switch to an alternative by age 50
What must be considered in older women requesting the injection?
- it can cause osteoporosis
- this is significant in older women + patients on steroids for asthma / inflammatory conditions
- it is UK MEC 2 in women > 45 and they should switch to an alternative by age 50
What is the mechanism of action of the DMPA?
inhibition of ovulation:
- it inhibits FSH secretion by the pituitary gland
- this prevents the development of follicles in the ovaries
other actions:
- thickening of cervical mucus
- altering the endometrium to make it less accepting of implantation
What advice is given regarding condom use when starting the DMPA injection?
- no additional protection is required if started on day 1 - 5 of the cycle
- if started at any other time, condoms should be used for 7 days
What do the guidelines state about the frequency of injections?
women need to have injections every 12-13 weeks
- it can be given as early as 10 weeks
- and it can be given as late as 14 weeks where necessary (but this is not licensed)
What are the 2 side effects that are unique to the injection?
osteoporosis & weight gain
What are women told about their bleeding pattern prior to starting the injection?
- with any progesterone-only contraception, changing to the bleeding schedule is common
- it cannot be predicted how the woman will respond
- bleeding may become irregular, heavier or prolonged (usually temporary)
- most women will stop bleeding altogether** after **1 year of use
What are the side effects associated with the DMPA injection?
- weight gain
- acne
- reduced libido
- mood changes
- headaches / flushes
- alopecia (hair loss)
- skin reactions at injection sites
- OSTEOPOROSIS
Why can the DMPA injection cause osteoporosis?
- oestrogen helps to maintain bone mineral density
- oestrogen is mainly produced by the follicles in the ovaries
- suppressing the development of follicles reduces the amount of oestrogen produced
- this results in decreased bone mineral density
How does the DMPA injection influence cancer risk?
slight increase in risk of breast + cervical cancer
slight decrease in risk of ovarian + endometrial cancer
What is the bleeding pattern typically like when starting the injection?
- irregular bleeding is very common in the first 6 months
- most women experience amenorrhoea** after using the injection for **1 year
- if irregular bleeding persists after 6 months, alternative causes must be excluded
- cervical screening, pregnancy test + sexual health screen
If problematic bleeding persists whilst taking the injection, what other medication can be given?
- the COCP** is taken in addition to the injection for **3 months
- this can settle problematic bleeding
- a short 5 day course of mefenamic acid (NSAID) is an alternative to stop bleeding
What are the benefits associated with the injection?
- improvement in dysmenorrhoea
- improvement in endometriosis-related symptoms
- reduces severity of sickle cell crisis in sickle cell anaemia
What is significant about the DMPA injection and drug reactions?
it is NOT affected by enzyme-inducers
Where is the progesterone-only implant positioned?
- it is placed in the upper arm
- it is beneath the skin and above the subcutaneous fat
- it slowly releases progestogen into the systemic circulation
How frequently does the implant need to be replaced?
every 3 years
What implant is used in the UK?
What does it contain and who can have it?
Nexplanon
- it contains 68mg etonogestrel
- it is licensed for use between the ages of 18 and 40
What are the contraindications to Nexplanon?
UK MEC 4:
- active breast cancer
UK MEC 3:
- severe liver cirrhosis / cancer
- continuing use following cardiovascular accident
- currently taking enzyme inducers
What is the mechanism of action of the implant?
- inhibition of ovulation
- thickening of cervical mucus
- altering the endometrium to make it less acceptable to implantation
What advice is given about condom use after having the implant inserted?
- no additional protection is required if the implant is inserted on day 1-5 of the cycle
- if insertion is at any other time, condoms should be used for 7 days
How is the implant inserted and its position checked?
- lidocaine is used as a local anaesthetic
- a special device is used to insert the implant horizontally, beneath the skin and above the subcutaneous fat
- it is inserted ⅓ of the way up the upper arm, on the medial side
- it should be palpable immediately
- pressing on one end of the implant should make the other end pop up against the skin
How is the Nexplanon implant removed?
- lidocaine is used
- a small incision is made in the skin at one end of the implant
- the device is removed using pressure on the other end or forceps
When is contraception required after removal of the implant?
contraception is required IMMEDIATELY after removal
In which patients may the Nexplanon implant be the contraceptive of choice?
Unlike the COCP…
- it can be used in obese patients
- it does not affect the VTE risk
Unlike the depo injection…
- it has no effect on bone mineral density
- it does not cause weight gain
What are the benefits to the Nexplanon implant?
- it can improve dysmenorrhoea
- it can make periods lighter / stop altogether
- there is no need to remember to take pills
What are the drawbacks to the use of the Nexplanon implant?
- it requires a minor operation to be removed
- worsening of acne
- no protection against STIs
- can cause problematic bleeding
- implants can become bent / fractured
- implants can become impalpable / deeply implanted
- this requires further investigations / management
What advice is given to women about palpating their implant?
- women should palpate the implant occasionally
- if the implant becomes impalpable, extra contraception is required until it is located
- USS or XR can be used to locate the implant as it contains barium sulphate
- referral to a specialist removal centre may be required
If the implant cannot be detected after USS, what should be done?
CXR
- rarely, the implant can enter blood vessels and migrate through the body
- there is a risk of an implant entering a pulmonary artery
What is the bleeding pattern typically like when using the implant?
- ⅓ have infrequent bleeding
- ¼ have frequent / prolonged bleeding
- 1/5 have no bleeding
- the remainder have normal regular bleeds
If bleeding is problematic when using the implant, what can be done?
- COCP** is given for **3 months in addition to the implant
- this helps to settle the bleeding
- only suitable if there are no contraindications
