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Levonorgestrel
From WikEM
Contents
Administration
- Type: Contraceptive
- Dosage Forms:
- Routes of Administration: oral, intrauterine (IUD)
- Common Trade Names: Plan-B, most brands of combination OCPs, Mirena
Adult Dosing
- Emergency contraception: 0.75mg PO q12 x 2 OR 1.5mg PO once, as soon as possible within 72 hours of unprotected sex
Pediatric Dosing
- See above
Special Populations
- Pregnancy Rating: X
- Lactation risk: Infant risk cannot be ruled out
- Renal Dosing: no adjustment
- Hepatic dosing: no adjustment
Contraindications
- Allergy to class/drug
- Pregnancy
- IUDs only:
- Active pelvic infection or STD
- Immunocompromise
- Known or suspected breast, uterine, or cervical cancer
- Acute liver disease or liver tumor
- Structural uterine anomaly including fibroids that distort uterine cavity
Adverse Reactions
Serious
- Pills:
- DVT/PE, stroke, MI
- Depression, suicidality
- IUDs:
- Ectopic pregnancy
- Uterine perforation
- PID, sepsis
Common
- Nausea, abdominal pain
- Headache, dizziness
- Abnormal vaginal bleeding, breast tenderness, ovarian cysts
- Pills:
- Acne
- Fatigue
- IUDs:
- Pelvic pain, vulvovaginitis
- Irregular menses, hypomenorrhea/amenorrhea
Pharmacology
- Half-life: Oral: 17-27.5h
- Metabolism: Hepatic, primarily via CYP3A4
- Excretion: Renal, fecal
Mechanism of Action
- Progestogen; inhibits ovulation or fertilization by altering tubal transport of sperm and/or ova
