What is the recommended dose of medroxyprogesterone (MPA) for menstrual induction?

Medroxyprogesterone Dosage for Menstrual Induction

For menstrual induction in women with secondary amenorrhea, medroxyprogesterone acetate should be given at a dosage of 5-10 mg daily for 5-10 days, with 10 mg daily for 10 days being optimal for inducing secretory transformation of an adequately primed endometrium. 1

Dosing Guidelines

The FDA-approved dosing for medroxyprogesterone acetate (MPA) in cases of secondary amenorrhea is clear:

• Standard dose: 5-10 mg daily for 5-10 days 1
• Optimal dose for secretory transformation: 10 mg daily for 10 days 1
• Expected response: Progestin withdrawal bleeding typically occurs within 3-7 days after discontinuing MPA therapy 1

Administration Timing

The timing of administration depends on the clinical scenario:

• Secondary amenorrhea: MPA therapy may be started at any time 1
• Abnormal uterine bleeding: Begin on the calculated 16th or 21st day of the menstrual cycle 1
• Planned menstrual cycling: Women with recurrent episodes of abnormal uterine bleeding may benefit from planned menstrual cycling with MPA 1

Clinical Considerations

When prescribing MPA for menstrual induction, consider these important factors:

• Pregnancy testing: Before initiating therapy, ensure the patient is not pregnant, as MPA should not be used during pregnancy 1
• Endometrial priming: For optimal results, the endometrium should be adequately primed with either endogenous or exogenous estrogen before MPA administration 1
• Contraceptive effect: While MPA can be used for contraception in its injectable form (DMPA), the oral formulation used for menstrual induction is not a reliable contraceptive 2

Special Populations

Adolescents

• DMPA (injectable form) is safe and effective for use in adolescents 2
• Counseling about potential menstrual irregularities is important to improve continuation rates 2

Women with Recurrent Abnormal Bleeding

• Planned menstrual cycling with MPA may be beneficial 1
• Consider 5-10 mg daily for 5-10 days each month 1

Potential Side Effects

Common side effects of oral MPA include:

• Breast tenderness
• Breakthrough bleeding or spotting
• Headaches
• Nausea
• Mood changes
• Weight changes 1

Clinical Pitfalls to Avoid

1. Failure to rule out pregnancy: Always confirm the patient is not pregnant before initiating MPA therapy 1
2. Inadequate endometrial priming: For optimal results, ensure the endometrium has been adequately primed with estrogen 1
3. Confusion with DMPA: Do not confuse oral MPA dosing for menstrual induction with injectable DMPA dosing for contraception (150 mg IM every 13 weeks) 2
4. Overlooking contraindications: MPA should not be used in women with current or history of thromboembolism, liver disease, breast cancer, or unexplained vaginal bleeding 1
5. Expecting immediate results: Inform patients that withdrawal bleeding typically occurs 3-7 days after completing the MPA course 1

By following these evidence-based guidelines, clinicians can effectively use medroxyprogesterone acetate for menstrual induction in appropriate patients.