What is the recommended dose and administration schedule of Depot Medroxyprogesterone Acetate (DMPA) (Medroxyprogesterone Acetate) for contraceptive purposes, and what are the potential side effects and counseling considerations?

DMPA Injection Dosing and Administration

Administer DMPA as either 150 mg intramuscularly or 104 mg subcutaneously every 13 weeks (up to 15 weeks), with the first injection given during the first 5 days of menses to ensure the patient is not pregnant. 1

Dosing and Route of Administration

• Two formulations are available with equivalent effectiveness and side effects: 2

  • 150 mg intramuscular (IM) injection into the gluteal or deltoid muscle 1
  • 104 mg subcutaneous (SC) injection 2

• Shake the vial or prefilled syringe vigorously immediately before administration to ensure uniform suspension 1

Timing of First Injection

• Give the first injection ONLY during the first 5 days of a normal menstrual period 1

• Alternative timing for postpartum patients: 1

  • Within first 5 days postpartum if not breastfeeding
  • At sixth postpartum week if exclusively breastfeeding

• "Quick start" or "mid-cycle" initiation is acceptable if the provider is reasonably certain the patient is not pregnant 2

Repeat Injection Schedule

• Schedule repeat injections every 13 weeks (91 days) 2
• Injections can be given up to 2 weeks late (15 weeks from last injection) without requiring backup contraception 3, 1
• If more than 2 weeks late (>14 weeks): 3
  • Confirm patient is not pregnant before administering
  • Require backup contraception for 7 days after injection
• Many providers schedule adolescents every 11-12 weeks to allow buffer time for missed appointments 2
• No time limits exist on early injections if scheduling conflicts arise 3

Side Effects to Counsel About

Menstrual Changes (Most Common)

• Nearly all patients experience menstrual irregularities initially with unpredictable spotting and bleeding 2
• Bleeding patterns typically improve over time, with amenorrhea becoming common with continued use 2
• Pre-injection counseling about menstrual changes reduces discontinuation rates 2

Weight Gain

• Weight gain occurs in some but not all patients 2
• Weight gain status at 6 months strongly predicts future excessive weight gain with ongoing use 2

Bone Mineral Density

• DMPA causes reversible reductions in bone mineral density (BMD) 2
• BMD substantially recovers after discontinuation 2
• ACOG does not recommend limiting use to 2 years despite FDA black-box warning, as pregnancy prevention benefits outweigh risks 2, 3

Other Side Effects

• Additional possible adverse effects include: 2
  • Headache
  • Mastalgia (breast tenderness)
  • Hair loss
  • Change in libido

Delayed Return to Fertility

• Ovulation suppression may persist 15-49 weeks after the last injection 3
• Return to fertility typically takes 9-18 months after discontinuation 4

Patient Counseling Points

Contraceptive Efficacy

• Use backup contraception (condoms or abstinence) for the first 7 days after initial injection 2
• Typical use failure rate is approximately 6% in the first year 2
• Perfect use failure rate is 0.2% 5

STI Protection

• Counsel that condoms should be used at all times for STI protection, as DMPA provides no protection against sexually transmitted infections 2

Bone Health Measures

• All patients should receive counseling on skeletal health promotion: 2
  • Daily intake of 1300 mg calcium
  • 600 IU vitamin D daily
  • Regular weight-bearing exercise
  • Avoidance of smoking and alcohol

Special Considerations for HIV-Infected Patients

• Inform HIV-infected women that DMPA may or may not increase HIV transmission risk to partners 2
• Emphasize continued condom use for HIV prevention 2
• DMPA has no significant interactions with antiretroviral agents including efavirenz, zidovudine, lamivudine, nevirapine, and nelfinavir 2

Self-Administration Option

• Subcutaneous DMPA (104 mg) can be self-administered as an off-label use when prescribed by a provider 2, 6
• Self-administration improves access, autonomy, and continuation rates 6
• Critical implementation elements include: 2
  • Instruction on self-injection technique (in-person or via telemedicine)
  • Sharps disposal education
  • Access to follow-up care
  • Reinjection reminders

Common Pitfalls to Avoid

• Do not assume amenorrhea after DMPA is pathologic without ruling out other causes if it persists beyond 18 months after discontinuation 4
• Do not routinely monitor bone density or limit use to 2 years based solely on BMD concerns 2
• Do not fail to counsel about menstrual irregularities before first injection, as this significantly reduces discontinuation 2
• Do not forget to verify pregnancy status if injection interval exceeds 15 weeks 1