progestin-only implant

Indications

• prevention of pregnancy
  • subdermal etonogestrel-releasing implants are the most effective contraceptives available
• women with a body mass index (BMI) >30 kg/m2; can use a progestogen-only implant without restriction and without a reduction in contraceptive efficacy for the duration of the licensed use (Grade C)
• ok for use with migraine
• can safely be used by women who are breastfeeding

Dosage

/Administration:

• duration of use for the progestogen-only implant is 3 years
  • subdermal etonogestrel-releasing implants effective for 5 years
• can be inserted immediately following surgical abortion or (second part of) medical abortion or miscarriage
• inserted at the inner side of the upper arm (non-dominant arm) about 6-8 cm above the elbow crease in the groove between the biceps & the triceps (sulcus bicipitalis medialis)
• appropriate anaesthesia should be injected prior to insertion & removal
• use of prophylactic antibiotics to prevent endocarditis is not recommended
• no routine follow-up is required

Adverse effects

• overall risk of ectopic pregnancy is reduced when using progestogen-only implants when compared to using no contraception
• there is no evidence of a delay in return of fertility following removal of a progestogen-only implant
• bleeding: 20% of users will have no bleeding, almost 50% will have infrequent, frequent or prolonged bleeding; bleeding patterns are likely to remain irregular
• acne may improve, occur or worsen during the use of a progestogen-only implant
• early discontinuation (up to 43% within 3 years)
• no evidence of causal association
  • weight change, mood change, loss of libido
  • headache, ok for use with migraine
  • venous thromboembolism
  • clinically significant effect on bone mineral density
  • breast cancer risk.

Drug interactions

• efficacy of a progestogen-only implant is not diminished by non-liver enzyme-inducing antibiotics & that additional contraceptive protection is not required
• see progestin

Mechanism of action

• prevention of ovulation
• pregnancy rate associated with use of a progestogen-only implant is very low (<1 in 1000 over 3 years)

More general terms

• progestin-only contraceptive
• contraceptive implant

More specific terms

• etonogestrel implant (Implanon)