The purpose of this study was to assess the proportion of patients satisfied with their treatment after a change from a low-dose oral contraceptive (OC) to norethisterone acetate (NETA) because of inefficacy of OC on pain symptoms. To this end, prospective, self-controlled study was conducted on 153 women using OC as a treatment for endometriosis and with persistence of one or more moderate or severe pain symptoms. At baseline and during 12 months after a shift from OC to oral NETA, 2.5 mg/d, pelvic pain was measured by means of a 0- to 10-point numerical rating scale and a multidimensional categorical rating scale. Variations in health-related quality of life, psychological status, and sexual function were also evaluated with validated scales. At the end of the study period, participants indicated the degree of satisfaction with their treatment according to a 5-degree scale from very satisfied to very dissatisfied. A total of 28 women dropped out of the study, the main reason was intolerable side effects (n = 15). At 12-month assessment, 70% of participants were very satisfied or satisfied with NETA treatment (intention-to-treat analysis). Statistically significant improvements were observed in health-related quality of life, psychological status, and sexual function. At per-protocol analysis, almost half of the patients (58/125) reported suboptimal drug tolerability. However, complaints were not severe enough to cause dissatisfaction, drug discontinuation, or request for surgery. These encouraging results could be used to counsel women with symptomatic endometriosis not responding to OC and to inform their decisions on modifications of disease management.
Keywords: combined oral contraceptives; endometriosis; medical treatment; pelvic pain; progestins.