II. Definitions
- Progesterone Implant
- Subcutaneous inserted Progestin containing rod
III. Background
- Duration: Continuous Contraception for 3 years
- Progestin: Etonogestrel
- Release rate
- Initial: 60-70 mcg/day
- Tapers to 30 mcg/day
- Rod dimensions: (Lenth: 40 mm, Diameter 2 mm)
IV. Efficacy
- Nexplanon Failure rate: 1 per 2000 users
- Failure rate may be higher if >130% of Ideal Weight
- Several medications lower efficacy (see below)
- Implanon had a higher failure rate (1 in 1000) attributed to insertion technique
V. Drug Interactions: Medications that lower efficacy
- Phenobarbital and other Barbiturates
- Phenytoin, Fosphenytoin and other Hydantoins
- Carbamazepine
- Griseofulvin
- Protease Inhibitors
- Primidone
VII. Adverse effects
- Weight gain
- Acne Vulgaris
- Depression or Emotional lability
- Irregular Menstrual Bleeding
- Amenorrhea most common
- Frequent or prolonged bleeding occurs in 23% of patients (unlike IUD, often persists)
- Menorrhagia
- Bleeding 50% less with Doxycycline 100 twice daily for 5 days
- Weisberg (2006) Human Reproduction 21:295-302 [PubMed]
- Management
- See Depo Provera (DMPA)
VIII. Procedure: Insertion (<5 minutes)
- No incision needed
- Nexplanon comes inn Preloaded applicator
- Inserted into subcutaneous skin of arm
- Both patient and physician must palpate rod post-insert
IX. Procedure: Removal (<10 minutes)
- Infiltrate Local Anesthetic under Implanon
- Incision of 2-3 mm at distal tip of Implanon
- Nexplanon pushed from proximal end into incision
- Consider scraping with scalpel
- Make incision through fibrous sheeth around Implanon
- Remove by grasping Nexplanon rod with forceps
- Pearls for difficult removal
- Ultrasound if device cannot be palpated
- Middle of implant the only palpable part
- Make incision over palpable rod and grasp with vas clamp or curved hemostat
X. Protocol: Switching between contraceptives
- Starting Nexplanon
- Use pill, patch, ring, or barrier protection for the first 4 days after Implanon insertion
- Switch may be made before the scheduled end of use of the prior contraceptive
XI. References
- Welsh (2006) New Contraceptives, Lecture, Wyoming, MN
- Funk (2005) Contraception 71:319-26 [PubMed]
- Prine (2018) Am Fam Physician 98(5): 304-9 [PubMed]