How should I write the prescription for Depo‑Provera (medroxyprogesterone acetate) 150 mg, including the sig and quantity?

How to Write a Prescription for Depo-Provera 150 mg

Write the prescription as: Depo-Provera (medroxyprogesterone acetate) 150 mg/mL intramuscular injection; Sig: Inject 1 mL (150 mg) deep intramuscularly every 12 weeks (84 days); Quantity: 1 mL vial or 1 prefilled syringe.

Prescription Components

Drug Name and Formulation

• Generic/Brand: Medroxyprogesterone acetate injectable suspension / Depo-Provera CI
• Strength: 150 mg/mL
• Route: Intramuscular (IM) only 1

Sig (Directions)

• Dose: 1 mL (150 mg) deep intramuscular injection
• Frequency: Every 12 weeks (13 weeks/84 days) 2, 3
• Timing window: Can be given up to 2 weeks late (15 weeks from last injection) without requiring backup contraception 2

Quantity

• Dispense: 1 mL single-dose vial OR 1 mL prefilled syringe 1
• Refills: Write for 3 refills if providing for one year of coverage (4 injections total)

Critical Prescribing Details

Available Formulations

Depo-Provera CI comes in two presentations 1:

• 1 mL single-dose vial (NDC 0009-0746-30)
• 1 mL prefilled syringe with 22-gauge × 1.5-inch needle (NDC 0009-7376-11)

Administration Instructions

• Must shake vigorously before use 1
• Administer by deep intramuscular injection only
• Storage: Vials must be stored upright at 20-25°C (68-77°F) 1

Timing of Initiation

When starting Depo-Provera, timing determines need for backup contraception 3:

• If started within 7 days of menses: No backup needed
• If started >7 days after menses: Patient must abstain or use barrier methods (condoms) for 7 days
• Can be started anytime if reasonably certain patient is not pregnant 3

Required Pre-Administration

• Blood pressure measurement: NOT required (unlike combined hormonal contraceptives) 3
• Bimanual/pelvic exam: NOT required 3
• Pregnancy test: Only if uncertain about pregnancy status

Important Counseling Points to Document

Black Box Warning

The FDA label includes a boxed warning about bone mineral density loss 1:

• Should not be used for more than 2 years unless other methods are inadequate
• Greatest BMD loss occurs in first 2 years of use
• Particularly concerning for adolescents during peak bone accretion

Expected Side Effects

Document that patient was counseled about 1:

• Menstrual changes: 55% amenorrhea at 1 year, 68% at 2 years
• Irregular bleeding/spotting initially is normal
• Weight gain: Common side effect
• Delayed return to fertility: May take up to 18 months after last injection to conceive 1

Special Populations

• Breastfeeding: Delay initiation until 6 weeks postpartum if exclusively breastfeeding 1
• Adolescents: Use with caution due to BMD concerns; counsel about bone health 1

Common Pitfalls to Avoid

1. Don't prescribe the subcutaneous formulation (104 mg/0.65 mL) unless specifically intending off-label self-administration 2
2. Don't write "every 3 months" - be specific: "every 12 weeks" or "every 84 days"
3. Don't forget to specify IM route - this distinguishes it from subcutaneous DMPA
4. Don't prescribe without discussing the 2-year limitation due to BMD concerns
5. Don't require pelvic exam before prescribing - this is an unnecessary barrier to access 3

Sample Prescription Format

Rx: Depo-Provera (medroxyprogesterone acetate) 150 mg/mL injection
Sig: Inject 1 mL deep intramuscularly every 12 weeks
Disp: 1 mL vial (or 1 mL prefilled syringe)
Refills: 3