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Prescribing LARC: to Depo or not to Depo?

Carole O'Connor
RGN

Practice Nurse
Hastings

National Institute for Health and Clinical Excellence (NICE) guidelines published in 2005 stated that long-acting reversible contraception (LARC) is more cost-effective than combined oral contraception, even at one year of use. It was highlighted that if 7% of women switched from the contraceptive pill to LARC (to include Depo-Provera, Implanon and intrauterine devices), the NHS could save approximately £100m by reducing 73,000 unintended pregnancies per year.1

NICE also clearly stated in the document that there was "no evidence of fracture risk increase." In 2008, Department of Health figures showed that abortions in women under 20 had increased and new funding of £26.8m was announced to improve access to contraception.

Information about LARC was always available to our patients, but since the introduction of Quality and Outcomes Framework (QOF) targets there has been a push for this type of contraception to cut the numbers of unwanted teenage pregnancies and abortions, and ensure cost-effectiveness for the NHS. The higher the QOF scores the higher the financial gain to the surgery as each LARC advice carries a three-point evaluation.

How does it work?
Depo-Provera contains the hormone progestogen and works by thickening the cervical mucosa so that sperm finds it impenetrable, and by thinning the womb lining so that any fertilised egg cannot implant itself. This contraceptive has a failure rate of 0.1 in 100 women, with 99% effectiveness.
The level of hormone is high at commencement and slowly decreases throughout the time span of three months, but it never falls below the relevant level to prevent ovulation. However, there does seem to be very conflicting advice on age limitation and the reported side-effect of bone-thinning, leading to osteoporosis.

Osteoporosis
Most bone growth in women occurs in the first 20 years, and bone density reaches its peak at around age 30. The greatest bone loss occurs after the menopause, at around the age of 50. The World Health Organization (WHO) published a document in 2007 entitled Hormonal Contraception and Bone Health, in which it said that some bone density is lost while using Depo-Provera, with 5-7% lost in the hip and spine. The good news, however, is that bone density does recover after stopping the contraceptive.2

In 2000, the authors of a primary care handbook, Practice of Obstetrics and Gynaecology - A Textbook for General Practice and the DRCOG, recommended that the contraceptive should not be given to women over the age of 45 due to its "skeletal demineralising potential".3

A study undertaken in New Zealand suggested that women using Depo-Provera had a lower bone density than those who did not, but it was discovered later that the study had flaws.4 Further reports have been inconclusive, and it would appear we may have to wait some years for women using these contraceptive to age, for further evidence either way.
The WHO also recommends that teenagers and women over the age of 45 (who are losing bone density) may use progestin-only injectables if they and their healthcare professional decide it is the best method for the individual, even if it may decrease her bone density.

The Family Planning Association (FPA) booklet Contraceptive Injections: Your Guide recommends that Depo-Provera should be used with caution in women under the age of 18 and over the age of 45.5

Factors that increase the risk of developing osteoporosis include:

  • Smoking.
  • Heavy drinking.
  • Long-term use of steroids.
  • Close family history of osteoporosis.
  • Early menopause leading to lack of oestrogen.
  • Oestrogen loss caused by missing periods for six months due to extreme dieting, excessive exercise or eating disorders.
  • Some liver, thyroid and digestive systems disorders.

The menopause
When using this contraceptive, particularly in peri-menopausal women, a good diet including calcium and vitamin D will undoubtedly be beneficial to ensure good bone health. Alcohol and smoking should be reduced and maintaining a good exercise regime with weight-bearing exercise such as running and walking will be advantageous.

The peri-menopause (occurring around the age of 44) and the menopause (usually occurring between the ages of 49 and 51) can cause women to suffer symptoms including:

  • Tiredness.
  • Low mood.
  • Lower libido.
  • Menstrual cycle disturbance producing amenorrhoea.
  • Headache.
  • Loss of sleep.

However, all of the above can also be side-effects of Depo-Provera, according to the manufacturer, and approximately 25% of menopausal women experience no symptoms at all.6 So how do we know the difference? Depo-Provera will not mask the symptoms of the menopause as it only contains progesterone - falling levels of oestrogen cause the hot flushes and other symptoms.

Case study
A patient at our surgery is 52 years old and has been using Depo-Provera for over 10 years. She has regular check-ups, exercises, eats well and is not overweight. Her blood pressure is normally satisfactory, but is now slightly raised, and she still smokes five cigarettes per day.

As she is adopted we are unable to assess her family history regarding osteoporosis. Our patient says she has had no symptoms of peri-menopause. She has occasional "spotting" but this has happened regularly since starting on this contraception. She is not keen to change her method, but was not aware of the possible side-effects regarding bone thinning, leading to possible fractures. We have now advised her accordingly.

Her hormone levels were checked and everything was normal. Her blood pressure is being monitored but has now decreased (she advises there has been some stress at home). Obviously smoking cessation was given and she is considering stopping.
It has been decided at the surgery for this patient to remain on Depo-Provera for one more year, and then to cease and use alternative methods if required. She will, of course, be monitored each three-monthly visit.

Summary
It would appear this type of contraception is being used more regularly. It can be beneficial in young girls who have trouble remembering to take their daily contraceptive pill. Each time they visit a date could be made for their subsequent appointment. If they are forgetful, most have mobile phones and could set up a reminder for that day.

For older patients using Depo-Provera long term, information and advice should be given on the potential side-effects of bone thinning, leading to fractures, and how the menopause may affect this.

With so many facts and figures, and often conflicting advice on this form of contraception, it must surely be down to the patient and her advising clinician to fully discuss the options. The lifestyle, family history and health of each individual should undoubtedly be taken into consideration, but the final decision lies with the patient - it is her right to choose!

References
1. National Institute for Health and Clinical Excellence (NICE). Long acting reversible contraception. London: NICE; 2005.
2. World Health Organization (WHO). Hormonal Contraception and Bone Health. Geneva: WHO; 2007.
3. Chamberlain G, Bowen-Simpkins P. Practice of Obstetrics and Gynaecology - A Textbook for General Practice and the DRCOG. Oxford: Churchill Livingstone; 2000.
4. New Zealand Contraception and Health Study Group. New Zealand contraception and health study: design and preliminary report. NZ Med J 1986;99:283-86.
5. Family Planning Association (FPA). Contraceptive injections - your guide. Available from: www.cks.nhs.uk/patient_information_leaflet/contraceptive_injections_your...
6. Pfizer Ltd. Summary of Product Characteristics:Depo Provera. Available from: www.medicines.org.uk/emc/medicine/11121/SPC/depo-provera%20150mg~ml%20in...