Levonorgestrel

Mirena is a progestin-containing intrauterine system (IUS) indicated for: ; Prevention of pregnancy for up to 8 years ( 1.1 ) ; Treatment of heavy menstrual bleeding for women who choose to use intrauterine contraception as their method of contraception for up to 5 years. ( 1.2 ) 1.1 Contraception Mirena is indicated for prevention of pregnancy for up to 8 years; replace after the end of the eighth year.

12.1 Mechanism of Action The local mechanism by which continuously released LNG contributes to the contraceptive effectiveness of Mirena has not been conclusively demonstrated. Studies of Mirena and similar LNG IUS prototypes have suggested several mechanisms that prevent pregnancy: thickening of cervical mucus preventing passage of sperm into the uterus, inhibition of sperm capacitation or survival, and alteration of the endometrium .

With Terminal t½ estimated at 10–15 hrs depending on renal/hepatic reserve (Levonorgestrel) residence kinetics and F ≈ 51%–63% systemic availability after standard oral Levonorgestrel administration bioavailability, Levonorgestrel undergoes levonorgestrel undergoes cyp3a4-mediated hepatic metabolism prior to excretion and establishes therapeutic activity over time to peak concentration spans 1 to 3 hrs under levonorgestrel maintenance.

Standard adult regimens span 1.5 mg/1 Tablet, 19.5 mg/1 Intrauterine Device, 1.5 mg/1.5mg Tablet, 13.5 mg/1 Intrauterine Device, 52 mg/1 Intrauterine Device. Prescribers screen specifically against the use of mirena is contraindicated when one or more of the following conditions exist:; pregnancy or suspicion of pregnancy; for use as post-coital contraception (emergency contraception), while community micro-logs most frequently note headache (11% of reports), nausea (8.2% of reports), dizziness (6.1% of reports).