Contraception – Methods – Progesterone Only Injectables

Long Acting Reversible Contraceptives (LARCs)

  • Depot medroxyprogesterone acetate (DMPA).
    • Depo-provera  – for IM injection
    • Sayana-press – for subcut
  • Norethisterone Enantate (NET-EN) for IM injection – less widely used in the UK -good for short term use when partner has gone for vasectomy waiting for the all clear

 

  • They’re pretty effective – 0.2% fail in the first year, 6% overall failure rate

Risks / Benefits

  • Amenorrhoea or reduced bleeding is common – this may be useful for some women with mennorrhagia say
  • Can help with endometriaosis pain
  • No increased risk of ovarian or endometrial cancer and may be protective
  • It’s an option for women with sickle cell disease and may reduce the severity of the crisis pain
  • There is an assoication with reduced bone mineral denisty for DMPA but this is recoverable following discontinuation

Notes

  • Can be used in adolesences as long as other methods have been considered first
  • Must review these patients every two years to discuss risks/benefits of continuing

Risks/associations

  • Switch them to something else at age 50years – if they don’t want to stop – make sure they know the risks
  • There’s possibly a slight link between using DMPA and breast cancer – the risk drops back to normal after stopping using it
  • No risk between DMPA and venous thrombosis has been demonstrated (although small number of studies)
  • Jury is still out on risk of myocardial infarction and stoke
  • There is a slight increased risk of cervical cancer if DMPA is used for 5 years or longer –> make sure she’s up to date with her cervical smears & HPV vaccination
  • There is an association with weight gain particualrly in under 18year olds who are already heavy (BMI>30) (and if they gain more than 5% body weight in the first 6 months they are likely to go on gaining weight)
  • Little evidence out there but increaese acne/decreased libido/ mood swings/headaches/hot flushes and vaginitis have been reported
  • Some suggestion of increased transmission/aquasition of HIV has not been confirmed but is possible

 

 

  • Inject in gluteus or deltoid – if they’re super fat use a long needle or go for deltoid if IM, SC you can go for abdomen or anterior thigh
  • Need to return every 13 weeks for further injections
  • Can be up to 7 days late without needing additional cover
  • If they need it early you can give:
    • DMPA at ten weeks and
    • NET-EN (norethisterone enante) at 6 weeks (outside license)
  • DMPA’s efficiency is not effected by enzyme inducing drugs

 

Other notes

  • UPA-EC has the potential to reduce efficiency of hormonal contraception so they should take extra precautions for 14 days after UPA-EC
  • They need to start a new contraceptive at the time, or before the next injection is due if they are switching.
  • There can be a delay of fertility by up to a year after discontinuing the DMPA
  • Subcut injection seems to be more likely to have an injection site reaction than IM injection of DMPA
  • If there is problematic bleeding they can be offered the CHC off licence for three months either continuously or cyclically – longer term use hasn’t been studied
  • Mefenamic acid 500mg TDS for five day is another option

If theres