FDA Approval and Removal Interval for Mirena (Levonorgestrel-Releasing Intrauterine System)
The Mirena (52-mg levonorgestrel-releasing intrauterine system) is FDA-approved for up to 7 years of continuous use for contraception, although recent research supports its efficacy for up to 8 years. 1
Approved Duration of Use
The FDA approval for Mirena has evolved over time:
- Initially approved for 5 years
- Extended to 7 years based on clinical evidence
- Research now supports efficacy for up to 8 years 1
Efficacy During Extended Use
The Mirena Extension Trial demonstrated continued high contraceptive efficacy during extended use:
- Years 6-8 Pearl Index: 0.28 (95% CI: 0.03-1.00)
- 3-year cumulative failure rate: 0.68% (0.17-2.71%)
- Individual year Pearl Indexes:
- Year 6: 0.34 (0.01-1.88)
- Year 7: 0.40 (0.01-2.25)
- Year 8: 0.00 (0.00-1.90) 1
Other Levonorgestrel IUD Options and Their Durations
Other levonorgestrel IUDs have different approved durations:
- Skyla (13.5-mg levonorgestrel): approved for 3 years 2
- Liletta (52-mg levonorgestrel): initially approved for 3 years 3
Clinical Considerations for Removal and Replacement
When to Remove/Replace
- At the end of the FDA-approved duration (7 years for Mirena)
- Earlier if:
- Patient desires pregnancy
- Unacceptable side effects develop
- Medical conditions arise that contraindicate continued use
Follow-up Recommendations
- Consider performing examinations to check for the presence of IUD strings 2
- Assess for any changes in health status that would affect the method's appropriateness 2
Side Effects and Management
Common side effects include:
- Irregular bleeding patterns, especially in the first 6 months
- Amenorrhea (occurs in approximately 50% of users by 12 months) 4
- Spotting (decreases from 25% at 6 months to 8-11% at 18-24 months) 4
For management of bleeding irregularities:
- NSAIDs (5-7 days of treatment)
- Hormonal treatment with COCs or estrogen (10-20 days) if medically eligible 2
Contraindications
Mirena should be avoided in:
- Current purulent cervicitis
- Active gonorrhea or chlamydia infection
- Current pelvic inflammatory disease (PID)
- Decompensated liver cirrhosis 2
Return to Fertility
- Rapid return to fertility after removal 2, 1
- In the Mirena Extension Trial, the 12-month return-to-fertility rate was 77.4% among women who discontinued for desire of pregnancy 1
Patient Satisfaction
High satisfaction rates have been reported with extended use:
- 98.7% of participants who completed 8 years of use reported satisfaction with the Mirena IUD 1
- Continuation rate of 66.2% at the end of the second year in another study 4
The evidence strongly supports that Mirena maintains high contraceptive efficacy, favorable bleeding patterns, and a good safety profile through 8 years of use, though the current FDA approval is for 7 years.