Kyleena: A Levonorgestrel-Releasing Intrauterine System for Contraception
Kyleena is a low-dose levonorgestrel-releasing intrauterine system (LNG-IUS) that provides highly effective contraception for up to 5 years with a failure rate of less than 1%. 1
Overview and Efficacy
Kyleena contains 19.5 mg of levonorgestrel (LNG) and is one of several LNG-IUS options available for contraception. It belongs to the category of long-acting reversible contraceptives (LARCs), which are considered highly effective with pregnancy rates of less than 1% per year during typical use 2.
Key characteristics of Kyleena:
- Contains 19.5 mg of levonorgestrel
- Licensed for contraception for up to 5 years
- Releases approximately 17.5 μg/day of levonorgestrel initially, decreasing to 7.4 μg/day after 5 years
- Smaller physical dimensions than higher-dose LNG-IUS options like Mirena
Mechanism of Action
Kyleena works through several mechanisms:
- Local release of levonorgestrel into the uterine cavity
- Thickening of cervical mucus, preventing sperm penetration
- Inhibition of sperm motility and function
- Alteration of the endometrium, making it less receptive to implantation
- Suppression of endometrial growth, often leading to reduced menstrual bleeding
Clinical Benefits Beyond Contraception
While Kyleena's primary indication is contraception, it offers additional benefits:
- Reduced menstrual bleeding: Most users experience a significant reduction in menstrual blood loss over time 3
- Improved hemoglobin levels: Due to reduced menstrual bleeding
- Reversible contraception: Fertility returns promptly after removal
Side Effects and Considerations
Common side effects include:
- Altered bleeding patterns: Most women will notice changes in bleeding patterns, particularly during the first months of use. Some may experience irregular spotting initially 3
- Hormonal side effects: Though less common due to the low systemic absorption, some users may experience headaches, acne, or breast tenderness
- Rare complications: While uncommon, potential complications include expulsion, perforation, and ectopic pregnancy if contraceptive failure occurs 4
Appropriate Candidates
Kyleena is appropriate for:
- Women seeking long-term, highly effective contraception
- Both nulliparous and parous women
- Women who desire reduced menstrual bleeding
- Women who prefer a lower hormonal dose than other LNG-IUS options
Contraindications
Kyleena should not be used in women with:
- Active pelvic inflammatory disease
- Pregnancy or suspected pregnancy
- Abnormal uterine bleeding of unknown cause
- Uterine or cervical malignancy
- Acute liver disease or liver tumor
Special Considerations for Specific Populations
Women with Rheumatic and Musculoskeletal Diseases (RMD)
For women with RMD who have neither systemic lupus erythematosus (SLE) nor positive antiphospholipid antibodies (aPL), LNG-IUS options like Kyleena are strongly recommended as highly effective contraceptive methods 2.
Women with SLE
For SLE patients with stable or low disease activity who are not positive for aPL, LNG-IUS options like Kyleena are conditionally recommended due to their high efficacy and low failure rates 2.
Women with Positive Antiphospholipid Antibodies
LNG-IUS options like Kyleena are strongly recommended for women with positive aPL, as they avoid the thrombotic risks associated with estrogen-containing contraceptives 2.
Adolescents
Kyleena can be appropriate for adolescents seeking long-term contraception. The American Academy of Pediatrics notes that IUDs are safe for nulliparous adolescents and have very low failure rates 2.
Practical Considerations
- Insertion timing: Can be inserted at any time during the menstrual cycle if pregnancy has been ruled out
- Backup contraception: May be needed for 7 days if not inserted during menses
- Return to fertility: Prompt return to fertility after removal
- Duration of use: Approved for up to 5 years of continuous use
Comparison to Other LNG-IUS Options
Kyleena (19.5 mg LNG) represents a middle option between:
- Jaydess/Skyla (13.5 mg LNG, 3-year duration)
- Mirena (52 mg LNG, 5-7 year duration)
The choice between these options may depend on factors such as desired duration of use, uterine size, and preference for bleeding patterns 5.
Conclusion
Kyleena offers a highly effective, long-acting, reversible contraceptive option with the additional benefit of reduced menstrual bleeding. Its lower hormone dose compared to some other LNG-IUS options may be preferable for certain women, while still maintaining excellent contraceptive efficacy.