Pharm
Implanon
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Implanon
, Nexplanon, Etonogestrel Drug Implant, Progesterone Implant, Contraceptive Implant
Definition
Subcutaneous inserted
Progestin
containing rod
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)
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
Drug Interactions
Medications that lower efficacy
Phenobarbital
and other
Barbiturate
s
Phenytoin
,
Fosphenytoin
and other
Hydantoin
s
Carbamazepine
Griseofulvin
Protease Inhibitor
s
Primidone
Safety
Safe in
Lactation
Ovulation
resumes within 3 weeks of removal
Adverse effects
Weight gain
Acne Vulgaris
Depression or Emotional lability
Irregular
Menstrual Bleeding
Amenorrhea
most common
Menorrhagia
Bleeding 50% less with
Doxycycline
100 bid x5 days
Weisberg (2006) Human Reproduction 21:295-302 [PubMed]
Procedure
Insertion (<5 minutes)
No incision needed
Nexplanon comes inn
Preload
ed applicator
Inserted into subcutaneous skin of arm
Both patient and physician must palpate rod post-insert
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
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
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]
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