Comparison of dienogest versus combined oral contraceptive pills in the treatment of women with adenomyosis: A randomized clinical trial

Objective: To compare the efficacy and safety of dienogest with combined oral contraceptives (COCs) for treating adenomyosis-associated symptoms. Methods: This was a randomized clinical trial including women with symptomatic adenomyosis conducted from March 1, 2019 to August 1, 2020 at Assiut Woman's Health Hospital, Egypt. Participants were randomly assigned to the dienogest group or COCs group. The primary outcome was the level of adenomyosis-associated pain from before to 6 months after treatment measured by a visual analog scale (VAS). Changes in the uterine bleeding pattern, uterine volume, and uterine artery blood flow were also reported. Results: The VAS score of pain was significantly decreased in both groups; however, the decreased rate was more pronounced in the dienogest group (3.21 ± 1.18) in comparison with the COCs group (4.92 ± 1.22). Bleeding pattern was improved greatly; uterine volume and uterine artery blood flow decreased significantly in the dienogest group. However, women in the dienogest group reported a higher rate of side effects. Conclusion: Dienogest and COCs are effective in treating adenomyosis-associated symptoms after 6 months of use but dienogest is more effective. The decrease in uterine volume and uterine artery blood flow may be the cause of the treatment effect. Dienogest carries a higher risk of side effects. Clinical trial.gov: NCT03890042.