What are the oral Medroxyprogesterone Acetate (MPA) regimens for the treatment of endometrial hyperplasia without atypia?

Oral MPA Regimens for Endometrial Hyperplasia Without Atypia

For endometrial hyperplasia without atypia, oral medroxyprogesterone acetate (MPA) should be administered as 10 mg daily continuously for at least 6 months, as this regimen achieves superior regression rates (96%) compared to cyclic dosing (69%). 1

Recommended Dosing Regimens

Continuous Daily Therapy (Preferred)

• MPA 10 mg orally once daily for 6 months 1
• This continuous regimen demonstrates 96% response rates in achieving endometrial normalization 1
• Continuous therapy is significantly more effective than cyclic administration for non-atypical hyperplasia 1

Cyclic Therapy (Less Effective Alternative)

• MPA 10 mg orally daily for 10-14 days per menstrual cycle for 6 months 2, 3
• This cyclic regimen shows only 69% response rates, making it substantially inferior to continuous dosing 1
• The FDA label supports 10 mg daily for 12 days per cycle when used for endometrial protection in postmenopausal women on estrogen therapy 2
• Cyclic progestogens should generally be avoided for hyperplasia treatment given their lower efficacy 1

Treatment Duration and Monitoring

Initial Treatment Phase

• Assess response at 6 months with repeat endometrial sampling (D&C or biopsy) 4, 1
• If hyperplasia persists after 6 months of continuous MPA, consider switching to levonorgestrel-IUD which shows 100% regression rates 1, 5
• If proliferative or non-atypical hyperplasia persists, continue the same progestin for an additional 3 months 3

Long-Term Surveillance

• High relapse risk of 41% occurs within 24 months after stopping therapy 6
• Consider prolonging progestogen therapy beyond 6 months to reduce relapse risk 6
• Re-evaluate clinically every 6 months after treatment completion 4
• Relapse rates are similar regardless of whether continuous or cyclic MPA was used initially 6

Important Clinical Considerations

Comparative Efficacy

• MPA 10 mg daily shows 36.7% resolution rates when used cyclically for simple hyperplasia without atypia 3
• Levonorgestrel-IUD achieves 100% response rates and is superior to oral MPA for this indication 1, 5
• At 2-year follow-up, 6-month LNG-IUD treatment shows 100% success versus 64% for oral MPA 5

Common Pitfall to Avoid

• Do not use cyclic MPA regimens (10 days per month) as first-line therapy for endometrial hyperplasia without atypia 1
• While cyclic dosing is FDA-approved for endometrial protection during estrogen therapy, it is significantly less effective than continuous dosing for treating established hyperplasia 2, 1

When to Consider Alternative Therapy

• If patient fails to respond to 6 months of continuous oral MPA, transition to levonorgestrel-IUD 1, 5
• For younger patients desiring fertility preservation, levonorgestrel-IUD may be preferred as first-line therapy given superior efficacy 5