What are the recommended injection and implant contraceptives, such as Depo-Provera (medroxyprogesterone acetate) and Nexplanon (etonogestrel), for effective long-acting reversible contraception?

Injection and Implant Contraceptives for Long-Acting Reversible Contraception

Long-acting reversible contraceptives (LARCs), particularly the etonogestrel implant (Nexplanon) and intrauterine devices (IUDs), are recommended as first-line contraceptive options due to their superior efficacy, with failure rates less than 1%, compared to injectable contraceptives like Depo-Provera which has a 6% failure rate with typical use. 1

Contraceptive Implants

Etonogestrel Implant (Nexplanon)

• Single-rod subdermal implant containing etonogestrel (active metabolite of desogestrel)
• Highest efficacy of all reversible contraceptives with 0.05% failure rate 1
• FDA-approved for 3 years, though evidence suggests effectiveness for up to 4-5 years 2
• Requires insertion by trained clinician into the inside of the upper arm 3
• 84% continuation rate at 1 year (highest among reversible methods) 1

Benefits:

• User-independent (eliminates adherence issues)
• Rapid return to fertility after removal
• Can be inserted immediately postpartum
• Suitable for women with medical comorbidities 1

Considerations:

• Main side effect is unpredictable bleeding/spotting (primary reason for discontinuation) 1
• Potential drug interactions with hepatic enzyme-inducing medications (e.g., efavirenz) may reduce efficacy 1
• Backup contraception needed for 7 days if not inserted within first 5 days of menstrual cycle 3

Injectable Contraceptives

Depot Medroxyprogesterone Acetate (DMPA/Depo-Provera)

• Intramuscular injection administered every 3 months (13 weeks)
• 6% failure rate with typical use 1
• 56% continuation rate at 1 year 1

Administration:

• 150mg deep IM injection in gluteal or deltoid muscle
• First injection must be given within first 5 days of normal menstrual period, within 5 days postpartum if not breastfeeding, or at 6 weeks postpartum if exclusively breastfeeding 4

Important Warning:

• Associated with significant bone mineral density (BMD) loss
• Should be used as long-term birth control (>2 years) only if other methods are inadequate
• Particular concern during adolescence and early adulthood (critical period of bone accretion)
• BMD loss appears partially reversible after discontinuation 4

Comparative Efficacy and Selection Algorithm

1. First-line options (failure rate <1%):

   • Etonogestrel implant (Nexplanon): 0.05% failure rate
   • Levonorgestrel IUDs: 0.2% failure rate
   • Copper IUD: 0.8% failure rate

2. Second-line option (failure rate 6%):

   • DMPA injection (Depo-Provera)

3. Decision factors for selecting between first-line options:

   • Duration needed: Copper IUD (10 years) > Levonorgestrel IUDs (3-5 years) > Nexplanon (3 years)
   • Medical considerations:
     • For patients with SLE or positive antiphospholipid antibodies: IUDs preferred 1
     • For patients at risk of osteoporosis: Avoid DMPA 4
     • For patients on enzyme-inducing medications: Consider IUDs over implant 1

Special Considerations

Adolescents

• LARCs are recommended as first-line options for adolescents 1
• Implants and IUDs are safe and appropriate for nulliparous adolescents
• Particular caution with DMPA in adolescents due to bone density concerns 4

Postpartum Contraception

• Immediate postpartum LARC placement is safe and effective 1
• Implants can be placed before hospital discharge
• Reduces barriers to effective contraception and prevents short-interval pregnancies 1

Women with Medical Comorbidities

• For women with medical conditions that increase pregnancy risks, LARC methods are particularly beneficial 1
• For women with rheumatic diseases, IUDs or implants are strongly recommended over less effective options 1

Counseling Points

• Discuss dual method use (LARC + condoms) for STI protection 1
• Inform about potential changes in menstrual bleeding patterns
• Emphasize high efficacy and convenience of LARCs
• Discuss immediate vs. delayed insertion options

Common Pitfalls to Avoid

1. Delaying LARC insertion until weeks after delivery (missed opportunity)
2. Not considering drug interactions with implants
3. Using DMPA long-term in patients at risk for osteoporosis
4. Failing to counsel about expected changes in bleeding patterns
5. Not offering immediate postpartum LARC options

In summary, LARCs offer the most effective reversible contraception with minimal user adherence requirements. While both implants and IUDs are excellent first-line options, the specific choice should be based on medical considerations, duration needs, and patient preferences, with Nexplanon and IUDs generally preferred over DMPA due to higher efficacy and fewer long-term concerns.