Dosage, efficacy, side effects and drug interactions

Warning

Dosing Interval

The recommended dosing interval for intramuscular DMPA (Depo-Provera®) and subcutaneous DMPA (Sayana Press®) is 13 weeks. This is outside the product licence for Depo-Provera®.

DMPA may be administered up to 14 weeks from the last injection without the need for additional contraceptive precautions. This is outside the product licence for Depo-Provera®.

 

 

Efficacy

Perfect use failure rate is 0.2% in the first year of use. Typical use is 6% in the first year of use.

Injectable contraceptives are long acting reversible contraceptives. Typical use failure rates are lower than failure rates for oral contraceptives. However, injectable contraceptives are less cost-effective than the implant and intrauterine methods because users are required to return more frequently

Side Effects

Common side effects

  • Change in menstrual pattern.
  • Delay in return of fertility.
    • Mean time to ovulation is 5.3 months following the preceding injection, i.e., 2 to 3 months following cessation of therapy.
  • Weight gain.
  • Injection site reactions - more common with subcutaneous than intramuscular injection

Less common adverse effects

  • Prolonged or very heavy bleeding – history and examination must be taken to exclude gynaecology pathology (e.g., pelvic infection, miscarriahe)
  • Anaphylaxis.
  • Galactorrhoea
  • Possible small increase in relative risk of breast and cervical cancer
  • Loss of bone mineral density (see below)

 

Drug Interactions

Women should be informed that the efficacy of progestogen-only injectable contraception is not reduced with concurrent use of medication  (including antibiotics and liver enzyme-inducing drugs) and the injection intervals do not need to be reduced.

Editorial Information

Last reviewed: 31/05/2024

Next review date: 31/05/2026

Author(s): West of Scotland Managed Clinical Network for Sexual Health Clinical Guidelines Group .

Version: 10.1

Approved By: West of Scotland Managed Clinical Network for Sexual Health