Letrozole combined with norethisterone acetate compared with norethisterone acetate alone in the treatment of pain symptoms caused by endometriosis

Abstract

The combination drug regimen was more effective in reducing pain and deep dyspareunia than norethisterone acetate; however, letrozole caused a higher incidence of adverse effects, cost more and did not improve patients' satisfaction or influence recurrence of pain.

Evaluation of endometriosis-associated pain and influence of conventional treatment: a systematic review

“…6,10,12,13,15,[17][18][19][20][22][23][24][26][27][28]31,32 The main results of these studies are summarized in Table 3.…”

“…Patients are advised to mark the position that reflects the degree of pain, with 0 being no pain and 10 or 100 considered the worst pain experienced. 15,27 One way to reduce the painful symptoms in patients with endometriosis is to use conventional treatment including surgery and/or medication.…”

“…Of the 17 studies that evaluated the influence of medication on decreasing pain levels, seven evaluated one drug alone 6,13,20,[26][27][28]32 and 10 evaluated drugs in combination. 10,12,15,[17][18][19][22][23][24]31 Thus, 3 studies employed contraceptives; 24,26,27 10 used isolated progestins; 10,12,13,15,17,19,20,22,23,28 5 used GnRHa, 6,10,22,24,32 one used danazol 23 and 4 used aromatase inhibitors. 12,15,19,22 The use of aromatase inhibitors for the treatment of endometriosis and its associated symptoms is justified by the fact that endometriotic tissue over-expresses aromatase, an enzyme key for the production of estrogen, noting that endometriosis is an estrogen-dependent gynecological condition.…”

Role of Aromatase Inhibitor in Endometriosis

“…However, the patient's compliance of the combined therapy is lower due to the higher incidence of unwanted side effects experienced by the patients such as joint pain and muscle aches. The recurrence of pain related symptoms was reported to be equal in both drug regimens, where the patients experienced pain symptoms within three months after ceasing treatment [27]. Another study reported by Abushahin et al showed that there was improvement of pain related symptoms after six months of Letrozole treatment combining with oral contraceptive pills.…”

“…Letrozole and Norethisterone acetate compared with progestin monotherapy [27]. However, the patient's compliance of the combined therapy is lower due to the higher incidence of unwanted side effects experienced by the patients such as joint pain and muscle aches.…”