Gynecology Book

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Contraceptive PatchAka: Transdermal Contraception, Ortho Evra

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  1. Pharmacokinetics
    1. Transdermal patch releases hormones at constant rate
      1. Ethinyl Estradiol 20 mcg/day
      2. Norelgestromin 150 mcg/day
  2. Technique: 4 week cycles
    1. Patch applied to unbroken skin for 3 weeks
      1. Upper arm
      2. Buttock
      3. Lower abdomen
      4. Upper trunk (not on breasts)
    2. Removed for 1 week for withdrawal bleeding
    3. New patch applied for 3 weeks
  3. Efficacy
    1. Failure rate: 0.88 pregnancies per 100 woman years
    2. Lower efficacy if weight >198 pounds (90 kg)
  4. Adverse effects
    1. Overall patch has similar adverse effects to OCP
    2. Transdermal specific adverse effects
      1. Contact Dermatitis reaction to patch
      2. Detachment rate: 2.8% of patches partially detach
    3. Increased adverse effects in first two months
      1. Vaginal spotting
      2. Breast discomfort (Mastalgia)
    4. Thromboembolism risk may be as high as twice the risk of Oral Contraceptives
      1. Cole (2007) Obstet Gynecol 109(2 Pt 1):339
  5. Benefits
    1. Higher compliance rate than with Oral Contraceptives
  6. References
    1. Herndon (2004) Am Fam Physician 69(4):853

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