Synonym: POSDI

This is a long-acting reversible contraceptive (LARC).

Available devices

Implanon®was the only contraceptive implant on the UK market but, from October 2010, it has been replaced with a bio-equivalent - Nexplanon®. This is different because:¹

• It comes in a preloaded applicator - to reduce insertion errors.
• It is radio-opaque, to allow location by X-ray.

Implanon® will now be discontinued, but you can continue to prescribe, dispense, or fit any remaining Implanon® stock that you may have.

Nexplanon® is a 4 cm flexible rod containing 68 mg etonogestrel (a progestogen) which is released slowly into the systemic circulation following subdermal insertion in the upper arm.² It must be removed after 3 years when it can then be replaced.³

Norplant®, which consists of 6 small rods, has been available in the past in the UK, along with Norplant-2® (also called Jadelle®), which is still used in some countries.²

Mechanism of action

The main mechanism of action of Nexplanon® is to inhibit ovulation. It also thickens the cervical mucus, inhibiting the passage of sperm to the uterus, as well as thinning the endometrium, preventing implantation were an egg to be fertilised.⁴

Epidemiology

2% of women between the ages of 16 and 49 use the implant.⁵

Patient selection

Nexplanon® is suitable for:

• Those who want a reliable but reversible form of contraception which does not require daily vigilance, like oral contraceptives do, or action at the time of intercourse, like barrier contraceptives require.
• Women who need a reliable form of contraception but who have contra-indications to oestrogen therapy - another alternative is the injectable progestogen-only contraception, Depo-Provera® (given every 12 weeks).

All patients should be carefully counselled before insertion - supplemented by a suitable patient information leaflet.

Failure rate

This is very low; most studies show no failures.
The National Institute for Health and Clinical Excellence (NICE) quotes a failure rate of less than 1 in 1,000 women in 3 years' use.^2,6 The main reason for 'failure' is incorrect timing of insertion, conception prior to insertion and failure of insertion.^4,7

Contra-indications³

• Pregnancy:
  • Exclude pregnancy before insertion; a history of recent normal menstruation or reliable use of another contraceptive is adequate.
  • If there is any doubt, suggest a urine pregnancy test pre-insertion.⁴
• Unexplained vaginal bleeding.
• Progesterone-dependent cancers.
• Current hydatid mole or choriocarcinoma (until human chorionic gonadotrophin (hCG) is undetectable).
• Current severe impairment of liver function (with abnormal LFTs) or history of liver adenoma or steroid-induced cholestatic jaundice.
• History of severe arterial disease or very high-risk factors:
  • Although there is no evidence of increased risk with Implanon®, the manufacturer advises that it be avoided in those with current active venous thromboembolism.
• Hypersensitivity to any components of Nexplanon®:
• They share the contra-indications of oral progestogen-only contraceptives:³
  • Acute porphyria, even if there is no history of active disease.
  • Liver adenoma.
  • Previous breast cancer - it can be used for >5 years provided there is no evidence of recurrence.
• It may be less effective when given with:
  • Liver enzyme-inducing drugs, e.g. anti-epileptic drugs.²
  • Antiretroviral drugs - the efficacy of both may be reduced, although the evidence on this is inconclusive.²

Benefits

• Studies of women using Norplant® show very low rates of ectopic pregnancy. There are no studies of the effect of Nexplanon® (or Implanon®) on rates of ectopic pregnancy but because it inhibits ovulation it is presumed that the rates are very low.² It is therefore suitable for women who have a history of ectopic pregnancy.⁴
• Dysmenorrhoea usually improves while using Nexplanon®.^2,8
• There is no evidence of delay in return to fertility on removal of Nexplanon®.²
• There is no evidence of reduced bone mineral density with Nexplanon®, unlike the contraceptive injection.⁴

Disadvantages²

• No protection is provided against sexually transmitted diseases.
• Unlike many methods of contraception, women cannot stop using an implant without the involvement of a properly trained healthcare professional:
  • Removal of Nexplanon® is usually a straightforward minor operation under local anaesthetic.
  • Possible complications include difficulty finding the rod and broken implants (frequency 0.2%).
  • If the implant cannot be palpated, ultrasound examination should be carried out before removal as the implant may have been inserted deeply.
• As with other progestogen-only methods, a change in bleeding pattern (amenorrhoea, irregular bleeding, menorrhagia) is common and is the main reason for early removal of Nexplanon®:⁹
  • These changes do NOT settle with time.
  • 33% of women have Implanon® removed early because of a change in bleeding pattern.
  • If there are no contra-indications, short-term cyclical oestrogens (either as a combined oral contraceptive or as ethinylestradiol), mefenamic acid and mifepristone may be of use in treating irregular or heavy bleeding. Counselling prior to insertion is important in decreasing discontinuation rates.^4,10,11,12

Side-effects

• Loss of libido and altered mood are rare side-effects of Nexplanon®. The NICE guidelines recommend that these should not be cited as side-effects when counselling women.
• Acne may improve or worsen while using Nexplanon®.
• If pregnancy occurs during use of hormonal contraception (including combined oral contraceptives), there is no evidence of increased risk of congenital malformation.¹³ There is, however, a theoretical risk of virilisation of the fetus, so the implant should be removed as soon as possible.
• Nausea, vomiting, dizziness and mastalgia. Breast pain may be caused by Implanon®.
• Breast cancer incidence is slightly raised during and for up to 10 years after use of injectable contraceptives.

There is no evidence that Nexplanon® causes headaches, weight gain, increased blood pressure, increased risk of venous thromboembolism or changes in lipids or glucose. There is also some evidence of a lesser effect on the reduction in bone mineral density.

Administration

Pre-insertion counselling

• Always take a full medical history (family, menstrual, contraceptive and sexual history).¹³
• Always give full counselling about the risks and benefits of the implant.
• Women should be advised to expect some discomfort and bruising at the site of insertion.
• Technically difficult insertions are unusual (<1 in 100).

Timing

• Implants may be inserted at any time in the menstrual cycle as long as the woman is 'reasonably certain' that she is not pregnant. This includes those switching from another hormonal method of contraception.²
• When switching from a levonorgestrel intrauterine system (LNG-IUS), the implant can be inserted immediately if the IUS was used correctly (or if the clinician is reasonably certain that the woman is not pregnant). The LNG-IUS should be continued for at least 7 days.¹⁴
• When switching from a copper intrauterine contraceptive device (Cu-IUCD), the implant may be inserted immediately if the IUCD was used correctly (or if the clinician is reasonably certain that the woman is not pregnant). The IUCD should be continued for at least 7 days.
• If the patient is amenorrhoeic or if insertion occurs after day 5 of the menstrual cycle, extra, non-hormonal contraceptive precautions should be taken for 7 days.^2,3
• After termination of pregnancy (TOP) in the first or second trimester, insertion may take place immediately.^2,14 If implanted >5 days after abortion or miscarriage, additional contraception is required for 7 days.
• After pregnancy, Nexplanon® should be inserted 21-28 days after delivery or TOP. It may be inserted immediately but this may be lead to an increase in irregular or heavy bleeding. If insertion takes place after day 28, additional contraception should be used for 7 days.²

Insertion

Practical training is required. Family planning trained doctors will provide this, either in primary care or family planning clinics.

• After injection of local anaesthetic, Nexplanon® is inserted into the subdermal tissue of the upper arm (flexor surface).³
• After insertion, both the health professional and the patient should examine the arm and be satisfied that the implant is in place, thus reducing the risk of insertion failures.

Follow-up

• Unless the woman experiences problems, no follow-up is required until removal is due 3 years after insertion.²

Document references

1. Nexplanon®, CEU Statement, Faculty of Sexual and Reproductive Healthcare, 2010
2. Long-acting reversible contraception, NICE Clinical guideline (October 2005); (the effective and appropriate use of long-acting reversible contraception)
3. Summary of Product Characteristics (SPC) - Nexplanon® 68 mg implant for subdermal use, electronic Medicines Compendium, October 2010
4. John Guillebaud. Your Questions Answered: Contraception, 4th Edition
5. Contraception and Sexual Health 2008/09, Office for National Statistics (2009)
6. Agrawal A, Robinson C; An assessment of the first 3 years' use of Implanon in Luton. J Fam Plann Reprod Health Care. 2005 Oct;31(4):310-2. [abstract]
7. Harrison-Woolrych M, Hill R; Unintended pregnancies with the etonogestrel implant (Implanon): a case series from postmarketing experience in Australia. Contraception. 2005 Apr;71(4):306-8. [abstract]
8. Sergent F, Clamageran C, Bastard AM, et al; Acceptability of the etonogestrel-containing contraceptive implant (Implanon). J Gynecol Obstet Biol Reprod (Paris). 2004 Sep;33(5):407-15. [abstract]
9. Power J, French R, Cowan F; Subdermal implantable contraceptives versus other forms of reversible contraceptives or other implants as effective methods of preventing pregnancy. Cochrane Database Syst Rev. 2007 Jul 18;(3):CD001326. [abstract]
10. Weisberg E, Fraser I; Australian women's experience with Implanon. Aust Fam Physician. 2005 Aug;34(8):694-6. [abstract]
11. Kaewrudee S, Taneepanichskul S, Jaisamraun U, Reinprayoon D. The effect of mefenamic acid on controlling irregular uterine bleeding secondary to Norplant(TM) use. Contraception 1999
12. Weisberg E, Hickey M, Palmer D, et al; A pilot study to assess the effect of three short-term treatments on frequent and/or prolonged bleeding compared to placebo in women using Implanon. Hum Reprod. 2006 Jan;21(1):295-302. Epub 2005 Nov 10. [abstract]
13. Bracken MB; Oral contraception and congenital malformations in offspring: a review and meta-analysis of the prospective studies. Obstet Gynecol. 1990 Sep;76(3 Pt 2):552-7. [abstract]
14. Progestogen-only Implants, Faculty of Sexual and Reproductive Healthcare (2009)