Efficacy of dienogest vs combined oral contraceptive on pain associated with endometriosis: Randomized clinical trial.

Objective: To compare the efficacy of dienogest with the combined oral contraceptive pill (COC) Yasmin for the control of endometriosis-associated pelvic pain.

Study Design: Seventy women with endometriosis-associated chronic pelvic pain, dysmenorrhoea or both for >6 months were randomized to either dienogest (Visanne) 2 mg/day or monophasic COC (Yasmin, 0.03 mg ethinyl estradiol and 3 mg drospirenone) for 24 weeks. The primary efficacy variable was change in non-cyclic pelvic pain and dysmenorrhoea from baseline to end of treatment, assessed using a visual analogue scale (VAS). The secondary efficacy variable was change in the Biberoglu and Behrman (B&B) scale scores for chronic pelvic pain, dysmenorrhoea and dyspareunia. Health-related quality of life (HRQoL) was evaluated using the Endometriosis Health Profile-30 (EHP-30) questionnaire at baseline and 24 weeks. Safety variables included incidence of side-effects, bleeding pattern and treatment tolerability.

Results: Both treatments improved the mean VAS score for endometriosis-associated pelvic pain significantly: mean difference 6.0 [95% confidence interval (CI) 4.9-7.1; p < 0.0001] in the dienogest group and 4.54 (95% CI 3.1-5.9; p < 0.0001) in the COC group; the difference between them was not significant (p = 0.111). Similarly, both dienogest and COC improved HRQoL in various core and modular segments of the EHP-30 questionnaire with comparable requirements for supplemental pain medication (p = 0.782 and 0.258 at 12 and 24 weeks, respectively), and redistribution of the B&B severity profile for chronic pelvic pain (p = 0.052 and 0.526 at 12 and 24 weeks, respectively), dysmenorrhoea (p = 0.521 and 1 at 12 and 24 weeks, respectively) and dyspareunia (p = 0.376 and 0.835, respectively). Nevertheless, dienogest was associated with fewer side-effects, and hence had a better safety and tolerability profile than COC.

Conclusions: Dienogest (2 mg/day) is comparable to the COC Yasmin for the relief of endometriosis-associated pelvic pain and improvement in HRQoL.

Clinical Trial Registration: Clinicaltrials.gov under number NCT04256200; date of registration 15/1/2020 (registered retrospectively).