Implanon

1. Definition
   1. Subcutaneous inserted Progestin containing rod
2. Background
   1. Duration: Continuous Contraception for 3 years
   2. Progestin: Etonogestrel
   3. Release rate
      1. Initial: 60-70 mcg/day
      2. Tapers to 30 mcg/day
   4. Rod dimensions: (Lenth: 40 mm, Diameter 2 mm)
3. Efficacy
   1. Failure rate: 1 per 1000 users
      1. Failure rate may be higher if >130% of Ideal Weight
      2. Several medications lower efficacy (see below)
4. Drug Interactions: Medications that lower efficacy
   1. Phenobarbital and other barbiturates
   2. Phenytoin, Fosphenytoin and other Hydantoins
   3. Carbamazepine
   4. Griseofulvin
   5. Protease Inhibitors
   6. Primidone
5. Safety
   1. Safe in Lactation
   2. Ovulation resumes within 3 weeks of removal
6. Adverse effects
   1. Weight gain
   2. Acne Vulgaris
   3. Depression or Emotional lability
   4. Irregular Menstrual Bleeding
      1. Amenorrhea most common
      2. Menorrhagia
         1. Bleeding 50% less with Doxycycline 100 bid x5 days
         2. Weisberg (2006) Human Reproduction 21:295-302
7. Procedure: Insertion (<5 minutes)
   1. No incision needed
   2. Implanon comes inn preloaded applicator
   3. Inserted into subcutaneous skin of arm
   4. Both patient and physician must palpate rod post-insert
8. Procedure: Removal (<10 minutes)
   1. Infiltrate local anesthetic under Implanon
   2. Incision of 2-3 mm at distal tip of Implanon
   3. Implanon pushed from proximal end into incision
   4. Make incision through fibrous sheeth around Implanon
   5. Remove by grasping Implanon rod with forceps
   6. Image with Ultrasound if device cannot be palpated
9. Protocol: Switching between contraceptives
   1. Starting Implanon
      1. Use pill, patch, ring, or barrier protection for the first 4 days after Implanon insertion
      2. Switch may be made before the scheduled end of use of the prior contraceptive
10. References
    1. Welsh (2006) New Contraceptives, Lecture, Wyoming, MN
    2. Funk (2005) Contraception 71:319-26