Comparison of Low-Dose Dienogest With Low-Dose Danazol for Long-Term Treatment of Adenomyosis

INTRODUCTION: The objective of this study was to compare low-dose dienogest with low-dose danazol for the long-term treatment of adenomyosis because evidence regarding the effects of its long-term use is scarce. METHODS: We compared 20 patients receiving low-dose dienogest treatment with 22 patients receiving low-dose danazol treatment for endometriosis including adenomyosis. We evaluated the effects and complications of low-dose dienogest treatment in comparison with those of low-dose danazol treatment. In addition, the values of serum hormones, tumor markers, and lipid metabolism were compared between both groups. This study was approved by the institutional review board. RESULT: The daily dose of dienogest could be decreased from 2.0 to 1.5 or 1.0 mg. Although irregular genital bleeding was recorded as an adverse effect, it was controllable; however, the monthly cost incurred by the low-dose dienogest treatment group was higher than that by the low-dose danazol treatment group. The daily dose of danazol could be decreased from 200 to 50 or 33 mg in patients with adenomyosis, but it was difficult to determine the adequate dose for individual patients. Some patients in the low-dose danazol treatment group developed polycythemia as an adverse effect, and the administration of the drug was therefore discontinued. There was no significant difference in the values of serum hormones, tumor markers, or lipid metabolism between both groups. CONCLUSION: We suggest that both low-dose dienogest and low-dose danazol are effective and safe for long-term management of endometriosis. However, the selection of either treatment for adenomyosis depends on each patient's baseline condition.