Bone loss during gonadotropin releasing hormone agonist treatment and use of nasal calcitonin. A randomized, placebo-controlled study on the effect of cyclic intermittent etidronate therapy on the bone mineral density changes associated with six months of gonadotropin-releasing hormone agonist treatment. A randomized double blind placebo controlled trial of the effects on bone metabolism of the combination of nafarelin acetate and norethisterone. Biochemical markers as predictors of bone mineral density changes after GnRH agonist treatment. Effects of add-back therapy on bone mineral density and pyridinium crosslinks in patients with endometriosis treated with gonadotropin-releasing hormone agonists. Hormone treatment related bone mineral content changes in Japanese women with endometriosis. Use of vitamin K2 (menatetrenone) and 1,25-dihydroxyvitamin D3 in the prevention of bone loss induced by leuprolide. Leuprolide in a 3-monthly versus a monthly depot formulation for the treatment of symptomatic endometriosis: a pilot study. Nafarelin: a new medical therapy for endometriosis. Leuprolide acetate depot and hormonal add-back in endometriosis: a 12-month study. Lupron Add-Back Study Group. Add-back therapy in the treatment of endometriosis: the North American experience. Gonadotropin-releasing hormone analogue (goserelin) plus hormone replacement therapy for the treatment of endometriosis: a randomized controlled trial. The effects of nafarelin and danazol on vertebral trabecular bone mass in patients with endometriosis. Bone mass in endometriosis patients treated with GnRH agonist implant or danazol. Depot leuprolide acetate versus danazol for treatment of pelvic endometriosis: changes in vertebral bone mass and serum estradiol and calcitonin. The effect of add-back treatment with tibolone (Livial) on patients treated with the gonadotropin-releasing hormone agonist triptorelin (Decapeptyl). Should add-back therapy for endometriosis be deferred for optimal results? Efficacy of every-other-day administration of conjugated equine estrogen and medroxyprogesterone acetate on gonadotropin-releasing hormone agonists treatment in women with endometriosis. Can hormone replacement therapy be used during medical therapy of endometriosis? Zoladex (goserelin acetate implant) in the treatment of endometriosis: a randomized comparison with danazol. The Zoladex Endometriosis Study Group. Gonadotropin-releasing hormone analogue plus hormone replacement therapy for the treatment of endometriosis: a randomized controlled trial.
Gonadotropin releasing hormone (GnRH) agonists have shown to be effective in the treatment of several sex-hormone-dependent conditions. However, their use could be limited by the bone loss they induce. To evaluate the use of nasal salmon calcitonin (sCT) in preventing this bone loss, 40 patients with endometriosis were treated for 6 months with triptoreline (3.75 mg monthly) and calcium (1 g daily), and randomized in three groups-placebo, sCT 100 IU daily and sCT 200 IU daily-in a prospective double-masked study. Dual-energy X-ray absorptiometry and biochemical parameters were used to evaluate the benefit of the treatment. At baseline, there were no statistically significant differences between the groups. After 6 months, estradiol and biochemical markers of bone metabolism were at postmenopausal levels, with no difference between the groups. There was no difference in bone loss in the three groups, at all sites. Mean lumbar bone loss was 4.01 +/- 2.59% (mean +/- SD) in this population. In this study dosages of 100 IU and 200 IU daily of nasal sCT were insufficient to prevent bone loss during GnRH agonist treatment. Our purpose was to determine whether intermittent cyclic etidronate therapy blocks the decline in bone density associated with gonadotropin-releasing hormone agonist therapy.
                Thirty-one premenopausal subjects who needed treatment with leuprolide (Lupron) 3.75 mg monthly for 6 months were randomized to etidronate or placebo. Bone turnover was assessed by measurement of serum calcium, phosphorus, alkaline phosphatase, and fasting urinary calcium/creatinine ratios. Bone density was measured by dual energy x-ray absorptiometry.
                Gonadotropin-releasing hormone treatment produced a significant decrease (4% to 10%) in bone density at the anteroposterior and lateral spine in placebo-treated patients (11). No significant change was demonstrated in etidronate-treated patients (15). Significant increases in serum calcium, phosphorus, alkaline phosphatase, and urinary calcium/creatinine ratios were noted in the placebo group. No significant change in these parameters were evident in the etidronate group.
                Etidronate blocks bone mineral density changes associated with gonadotropin-releasing hormone agonist therapy and normalizes serum and urine indicators of bone turnover. We observed the effects on bone metabolism of the addition of different doses of oral norethisterone during treatment with the GnRH agonist nafarelin (Synarel, Syntex).
                Ninety-four women with a subjective complaint of heavy menstrual blood loss or objective evidence of endometriosis received intra-nasal nafarelin 400 micrograms daily for 6 months and also received, in a randomized, double blind manner, either 0.7 mg (n = 24), 1.4 mg (n = 23) or 2.45 mg (n = 23) of oral norethisterone or placebo (n = 24) daily. Follow-up was continued for a further 6 months after treatment.
                Thirty-one patients (33%) left the study prematurely and three patients were non-compliant with the study drug. By 6 months significant increases in urinary calcium/creatinine ratio were seen, compared to baseline, in the nafareline and placebo (P = 0.001, n = 14), 0.7 mg (P = 0.04, n = 13) and 1.4 mg norethisterone groups (P = 0.009, n = 17) but not in the nafarelin or 2.45 mg norethisterone groups (P = 0.72, n = 16). Densitometry of the spine, however, showed decreases at 6 months in all groups: 6.14% (P = 0.0004, n = 11), 5.46% n = 0.0006, n = 13), 3.93% (P = 0.008, n = 14) and 4.04% (P = 0.004, n = 16) for the groups receiving nafarelin and placebo, nafarelin and norethisterone 0.7, 1.4 and 2.45 mg respectively. Six months after stopping nafarelin, with or without norethisterone, bone mass was not different from baseline.
                The concomitant daily use of up to 2.45 mg of norethisterone does not eliminate the bone demineralization seen during GnRH agonist therapy with nafarelin in premenopausal women. To evaluate bone biochemical markers as predictors of the efficacy of a hormone replacement therapy (HRT), we studied the bone changes induced by the cessation and return of ovarian function in 28 patients treated for 6 months with a GnRH agonist. This model reproduced the effects observed in postmenopausal women with high bone turnover treated with HRT. At the end of the treatment, Z scores were 1.8 +/- 0.3 for Crosslaps (CTx) and deoxypyridinoline (D-Pyr), and 1.1 +/- 0.2 for bone alkaline phosphatase (B-ALP) and osteocalcin (OC). This indicated an imbalance in bone remodeling with a high bone resorption. Bone mineral density (BMD) fell by 4.2 +/- 2.5%. The changes in BMD between the 6th and 12th months were 0. 34 +/- 2.24 and -1.73 +/- 3.25% at the lumbar spine and the femoral neck, respectively. Biochemical markers except urinary calcium and hydroxyproline measured at 6 months were positively correlated with the BMD changes at the lumbar spine. After the resumption of menstruation, 13 of 28 women displayed positive spine BMD changes between the 6th and 12th months; in this group, bone biochemical markers measured at 6 months were significantly higher (P = 0.02). Stepwise regression analysis showed that the association of B-ALP and D-Pyr measured at 6 months explained 40% of BMD variance and the association of B-ALP, PTH, and estradiol 56%. We conclude that measuring individual biochemical bone markers can help to predict the bone effect of an increase in the circulating estradiol in women with ovarian deficiency. Treatment of endometriosis with gonadotropin-releasing hormone agonists (GnRHa) is limited to 6 months because of possible adverse effects on bone metabolism. We designed a randomized, double-blind, placebo-controlled, prospective study of 27 patients with endometriosis who were given GnRHa with or without hormone add-back therapy (+ 20 microg of ethinyl estradiol with 0.15 mg desogestrel) designed to suppress the adverse effects of hypoestrogenism while preserving the efficacy of GnRHa. Both regimens showed significant improvements in endometriosis, dysmenorrhea, and pelvic pain; effects were significantly better in the GnRHa + placebo group. The GnRHa + placebo group had significantly higher serum calcium levels and a significantly higher loss of lumbar spine bone mineral density (BMD). Urinary levels of pyridinium crosslinks increased significantly in the GnRHa + placebo group, and declined to normal in the GnRHa + add-back group. The add-back therapy protects women taking GnRHas from severe loss of BMD and accelerated bone collagen resorption, but reduces the efficacy of the GnRHa. The effects of a GnRH agonist and danazol on bone mineral content (BMC) in Japanese women with endometriosis were investigated. Nineteen women with laparoscopically confirmed endometriosis were treated with buserelin (900 micrograms/d administered intranasally, 10 cases) or with danazol (400 mg/d p.o., 9 cases) for 6 months. Trabecular BMC of the 3rd lumbar vertebra was measured using quantitative computerized tomography before treatment, at the end of treatment and 6 months after treatment by the same radiologist who was not informed about the drug used. Serum estradiol and the biochemical parameters of bone metabolism were also measured. A significant decrease in BMC (10% on average; maximum 25.4%) was observed at the end of treatment with buserelin (p < 0.01) and this loss was only partially recovered 6 months after treatment. In the danazol group, however, a slight gain in BMC was observed. Buserelin suppressed serum estrogen levels much more than danazol did. Parameters of bone resorption tended to increase in the buserelin group. Because treatment with buserelin, but not with danazol, was always associated with a significant decrease in BMC at L3, repeated usage of buserelin may lead to cumulative bone loss in patients with endometriosis. The purpose of this study is to evaluate the efficacy of vitamin K2 and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] in preventing bone loss induced by estrogen deficiency during therapy with the GnRH agonist (GnRH-a) leuprolide. One hundred ten women (mean age, 46.2+/-0.5 yr), receiving leuprolide therapy for estrogen-dependent diseases (such as endometriosis and uterine leiomyomas), were randomly allocated into four groups (group A, leuprolide only; group B, leuprolide with vitamin K2; group C, leuprolide with 1,25-(OH)2D3; and group D, leuprolide with vitamin K2 and 1,25-(OH)2D3). Bone mineral density of the lumbar spine was measured by dual-energy x-ray absorptiometry before and after 6 months of treatment. Bone formation and resorption markers were also measured before and after 6 months of treatment. There were no significant differences in the background parameters among the four groups. Bone mineral density was reduced in all four groups, but the percent changes varied slightly, at - 5.25% (group A), -3.72% (P < 0.05 vs. group A) (group B), -4.13% (group C), and -3.59% (P < 0.01 vs. group A) (group D), respectively. Bone formation markers were significantly increased in all four groups, and the percent changes of bone formation markers were highest in group B. Bone resorption markers also increased significantly in all four groups after treatment of 6 months. Group B tended to have the highest percent changes of bone resorption markers among the four groups, but these increases were not significantly different between any of the groups. Vitamin K2, especially when combined with 1,25-(OH)2D3, can partially prevent bone loss caused by estrogen deficiency. However, because this effect is attributable mainly to the activation of bone formation, it is not sufficient to eliminate bone loss induced by GnRH-a therapy. An open-label randomized pilot study was conducted to evaluate the efficacy and acceptability of 6 months treatment with leuprolide in a 3-monthly versus a monthly i.m. depot injection for the relief of chronic pelvic pain in women with endometriosis. A total of 30 women aged 18-38 years were allocated to the 3-monthly depot arm (n = 15) or to the monthly depot arm (n = 15) after laparoscopic diagnosis of pelvic endometriosis. Mean (SD) deep dyspareunia scores according to a 0-3 point verbal rating scale decreased from 1.8 (0.9) at baseline to 1.3 (0.7) at the end of treatment in the 3-monthly depot group and from 2.1 (1.2) to 1.3 (0.7) in the monthly depot group. Corresponding values in non-menstrual pain scores fell from 2.1 (0.6) to 1.1 (0.3), and from 2.1 (0.8) to 1.2 (0.4) respectively, without statistically significant differences between the groups. Serum luteinizing hormone (LH) and 17 beta-oestradiol concentrations were significantly suppressed at 12 and 24 weeks compared with baseline values, without differences between the groups. The monthly depot caused a slightly more marked inhibition of serum follicle stimulating hormone (FSH) levels with respect to the 3-monthly preparation. Mean (SD) endometriosis scores at baseline and at 6-month follow-up laparoscopy were respectively 32.8 (25.1) and 12.2 (9.3) in the 3-monthly depot group and 29.0 (22.7) and 13.1 (15.3) in the monthly depot group (paired t-test, P < 0.05). Mean percentage decrease in lumbar spine bone mineral density was 5.2% in the former and 4.9% in the latter subjects. In the 3-monthly depot group, 13 women graded the tolerability of their treatment schedule as "good' compared with seven in the monthly depot group (chi 2 = 5.40, P = 0.02). nan To evaluate the efficacy and safety of a GnRH agonist, leuprolide acetate depot, alone and in combination with three hormonal add-back regimens in the management of endometriosis-associated pelvic pain.
                Two hundred and one patients were enrolled in this multicenter, randomized, double-blind, 1-year trial. All patients were given an intramuscular injection of leuprolide acetate depot 3.75 mg every 4 weeks. Patients were assigned to one of four treatment groups: Group A received placebos for progestin and estrogen, group B received norethindrone acetate 5 mg daily and placebo for estrogen, group C received norethindrone acetate 5 mg and conjugated equine estrogens 0.625 mg daily, and group D received norethindrone acetate 5 mg and conjugated equine estrogens 1.25 mg daily. Pelvic pain scores were assessed monthly, and bone density was measured after 24 and 52 weeks.
                By week 8, all four groups showed significant improvement in pelvic pain scores compared with baseline levels. A higher proportion of group D patients terminated the study prematurely due to a lack of improvement in symptoms. Group A experienced a 6.3 +/- 2.3% (P < or = .001) loss in bone density after 52 weeks of treatment, whereas bone density was preserved in all three add-back groups.
                The use of leuprolide acetate depot in combination with norethindrone acetate 5 mg alone, or with norethindrone acetate and conjugated equine estrogens 0.625 mg, provides effective suppression of pelvic pain symptoms associated with endometriosis while protecting against bone loss. nan To determine whether treatment of endometriosis with a GnRH analogue (GnRH-a; goserelin) combined with continuous estrogen and progestogen hormone replacement therapy (HRT) would prevent the hypoestrogenic effects, including loss of bone density, while maintaining efficacy for treatment of endometriosis.
                Randomized controlled trial.
                Fifty premenopausal women with laparoscopically diagnosed endometriosis (revised American Fertility Score for endometriosis implants equal to four or greater) and significant symptoms of dysmenorrhoea, dyspareunia, and other pelvic pain.
                Patients were randomized to receive either goserelin alone, 3.6 mg SC depot every 4 weeks for 24 weeks, or goserelin, 3.6 mg SC depot every 4 weeks for 24 weeks, plus HRT (25 micrograms transdermal 17 beta E2 daily and 5 mg medroxyprogesterone acetate orally daily) for 20 weeks commencing with the second goserelin injection.
                There was a significant reduction in the extent of pelvic endometriosis in both groups, with no difference between the groups. Both groups experienced an improvement in symptoms and signs, again with no difference between groups. Hypoestrogenic side effects of hot flushes and loss of libido were significantly less in the group that received HRT. The amount of bone mineral density loss was significantly less in the HRT group at the lumbar spine, although it was not prevented completely.
                The addition of HRT to GnRH-a for the treatment of endometriosis did not reduce the efficacy of treatment, and adverse hypoestrogenic effects were decreased, although not abolished. Single and dual-energy quantitative computed tomography (QCT) were used to measure spinal trabecular bone mineral content in 24 women treated with either nafarelin (15 patients) or danazol (nine patients) for endometriosis. Significant loss of bone mineral (-9.6 g/l; -5.9% P less than 0.001) was demonstrated after 6 months' treatment with nafarelin. This loss was reversible with no significant difference in the bone mineral measurement made before treatment and that made at 6 months after treatment was stopped (difference -1.95 g/l, NS). A small but statistically significant (+2.2 g/l, P less than 0.05) increase in bone mineral was measured in the group of patients treated with danazol for 6 months. The dual-energy QCT gave similar results, indicating little change in trabecular fat content. A significant correlation was demonstrated between mean serum oestradiol levels during treatment with nafarelin and the change in bone mineral (r = 0.655, P less than 0.005). Before treatment, the trabecular bone mineral content of the lumbar spine and femoral neck was not significantly different between endometriosis patients and age-matched controls (N = 26). In 17 subjects treated with a monthly goserelin implant, serum estradiol (E2) levels were suppressed into the menopausal range. Mean decreases from pre-treatment values in the lumbar spine and femoral neck were -5.7 and -3.8% at 3 months and -8.2 and -7.7% at 6 months of treatment, respectively; lumbar spine values were significantly different (P less than .05) from those of the control group, whose values changed little during the same period. Significant increases over baseline values were also observed in urinary calcium-creatinine ratio and serum alkaline phosphatase. In nine danazol-treated subjects, serum E2 levels were generally within the early follicular-phase range. There were no significant changes in bone assessments. Normal menses returned within 2 months after cessation of either medication. Six months after goserelin treatment, the lumbar spine and femoral neck bone mineral content was still reduced but to values not significantly different from the pre-treatment and control values; urinary calcium-creatinine ratio was decreased, whereas serum alkaline phosphatase was still elevated. The rapid and deep suppression of ovarian steroidogenesis by a monthly goserelin implant induced significant bone loss compared with the control and danazol groups. This loss was not reversed completely 6 months after cessation of treatment, but bone densities at that time were not different from those of controls. Studies of larger numbers of patients followed for longer periods will be required to resolve the question of complete reversibility. To determine changes in trabecular vertebral bone mass, serum E2, and serum calcitonin during and after therapy of pelvic endometriosis with depot leuprolide acetate (LA) or danazol.
                Prospective, randomized, double-blind study.
                Academic university hospital and department of obstetrics and gynecology.
                Twelve women with symptomatic pelvic endometriosis diagnosed and staged by laparoscopy.
                All patients received blinded treatment with either 3.75 mg JM depot LA given every month and daily placebo tablets (n = 6) or 800 mg oral danazol daily with a monthly placebo injection (n = 6) for 24 weeks.
                Quantitated computerized tomography of bone density of thoracic 12 to lumbar 4 vertebral bodies were determined before, at the end of 24 weeks of treatment, and 6 and 12 months after completing treatment. Gain or loss of bone mass was based against pretreatment levels. Serial serum levels of E2 and calcitonin before, throughout, and after therapy were compared with changes in bone mass.
                Bone loss with LA was 14.0% +/- 0.5% (mean +/- SEM), recovering to a deficit of 4.2% +/- 3.8% and 3.3%, 6 and 12 months after stopping therapy. Danazol increased bone by 5.4% +/- 2.2%, with a further gain to 8.2% +/- 3.5% and 7.5%, 6 and 12 months after stopping treatment. Serum E2 levels usually were < 25 pg/mL (conversion factor to SI unit, 3.671) with LA but > 47.3 pg/mL with danazol. Calcitonin levels did not change significantly with either treatment.
                Depot LA produced marked sustained hypoestrogenemia and significant bone loss with incomplete recovery 1 year after stopping treatment. Danazol maintained normoestrogenemia and increased bone mass with the gain maintained even 1 year after stopping therapy. To assess whether tibolone can prevent the bone loss and symptomatic side effects normally associated with GnRH agonist (GnRH-a) use and whether tibolone modifies the effect of GnRH-a on endometriosis.
                Prospective, double-blind, placebo-controlled, group comparative study.
                Gynecological research unit in a London teaching hospital.
                Twenty-nine patients with endometriosis and two with fibroids.
                Six months of treatment with 3.75 mg/mo IM triptorelin combined with daily tablets of either placebo or 2.5 mg tibolone.
                Daily symptom diary for hot flushes and bleeding episodes, laparoscopic scoring of endometriosis, endocrine and biochemical changes, and bone mineral density scans.
                Lumbar spine bone mineral density decreased significantly from baseline in the placebo group (-5.1%) but not in the tibolone group (-1.1%). The frequency of hot flushes and sweating episodes was reduced significantly by tibolone. There was no difference between the two treatment groups with regard to the endometriosis scores.
                The addition of tibolone to GnRH-a treatment reduces the bone loss and vasomotor symptoms that normally occur with GnRH-a, thus making long-term treatment with GnRH-a safer and more acceptable. It does not negate the therapeutic effect of GnRH-a on endometriosis. Add-back hormone replacement therapy has been shown to alleviate some of the hypo-oestrogenic side effects associated with gonadotrophin-releasing hormone agonists, including demineralisation of bone. Studies on patients with uterine fibroids have shown that concomitant add-back therapy reduced the efficacy of these agents, but that deferred administration was less detrimental. This trial set out to investigate if deferred add-back therapy could offer any advantages to patients with endometriosis compared with immediate therapy. Zoladex [goserelin acetate (3.6 mg every 4 weeks)] was given for 24 weeks either with placebo, with medrogestone (10 mg/day) for 24 weeks (immediate add-back therapy), or with placebo for 12 weeks followed by medrogestone (10 mg/day) for 12 weeks (deferred add-back therapy) to 123 patients. The number of responders measured using the Revised American Fertility Society score (decrease in this score of > or = 50%) was greatest in the immediate add-back therapy group, although there were no significant differences between groups. All three treatment groups showed significant decreases in bone mineral density compared with baseline but smaller losses were generally observed in the add-back groups. A significantly smaller number of patients in the immediate add-back group reported hot flushes during the first 12 weeks of treatment compared with the deferred add-back group. In conclusion, it appears that there is no extra advantage to patients with endometriosis being treated with goserelin in delaying the start of add-back therapy. We performed a randomized controlled study to determine the efficacy of add-backed therapy by every-other-day administration of 0.625 mg conjugated equine estrogen (CEE) and 2.5 mg medroxyprogesterone acetate (MPA) on GnRH agonists (GnRH-a) treatment in Japanese women with symptomatic endometriosis. At the end of treatment, serum estrone and estradiol levels in the add-back group (n = 11) were significantly higher than those in the control group (n = 10). The assessment of Beecham classification by bimanual examination, serum CA-125 levels, and the frequency of genital bleeding revealed no significant differences between the two groups. The add-back group showed reduced Kupperman indices relative to those of the control group, and could prevent the loss of bone density. These findings led to a conclusion that GnRH-a therapy added back by every-other-day administration of 0.625 mg CEE and 2.5 mg MPA was a safe and effective treatment for Japanese women with endometriosis.
                Copyright 2001 S. Karger AG, Basel nan To compare the efficacy, endocrine effects, and safety of Zoladex (goserelin acetate) and danazol in the treatment of premenopausal women with endometriosis in a multicenter, randomized, open study.
                Three hundred fifteen patients with stages I-IV endometriosis (revised American Fertility Society [AFS] classification) were treated with Zoladex, 3.6 mg every 28 days by subcutaneous injection, or danazol, 400 mg orally twice daily for 24 weeks. Efficacy was assessed by determination of pelvic signs and symptoms scores and revised AFS endometriosis scores. Endocrine effects were determined by measurements of hormone levels. Safety was evaluated by physical examination, laboratory indices, occurrence of adverse events, and bone mineral density changes.
                Both treatments significantly (P < .0001) reduced mean subjective signs and symptoms scores both during and after therapy. The mean percent reduction in the revised AFS endometriosis score after 24 weeks of treatment was 53% for Zoladex and 33% for danazol, and reduction in the endometrial implants score was 56% for Zoladex and 46% for danazol. Serum estradiol levels decreased to the postmenopausal range in the Zoladex group and to the early follicular phase range in the danazol group. Hypoestrogenic effects occurred more frequently with Zoladex, whereas androgenic side effects were more common with danazol. There was a higher percentage of withdrawals due to adverse events with danazol than with Zoladex. Mean bone mineral density decreased from baseline by 5.4% in the Zoladex group and increased by 1.0% in the danazol group at the end of treatment.
                Zoladex is as well tolerated and as effective as danazol in the treatment of premenopausal women with endometriosis. The aim of this study was to determine whether or not continuous combined HRT used with GnRH-a for the treatment of endometriosis can prevent hypoestrogenic side effects associated with GnRH-a.
                Forty premenopausal women with laparoscopically proven endometriosis entered the study. The patients were randomized into two groups. Group I (n = 19) received 3.75 mg i.m. leuprolide acetate (LA) every 4 weeks for 24 weeks. Group II (n = 21) received 3.7 mg LA combined with 1.25 mg oral conjugated equine estrogen (CEE) and 5 mg oral medroxyprogesterone acetate (MA).
                Total revised AFS score as well as total pelvic pain scores decreased significantly (P < .001) in both groups. However, a statistically significant difference of hot flushes and sweating was reported by women receiving LA + HRT as compared to those treated with LA alone (P < .001). Furthermore, the bone loss at the lumbar spine was 4.2% in group I compared to 0.9% in group II at the end of the study.
                This study suggests that 1.25 mg CEE + 5 mg MA is effective in preventing hypoestrogenic side effects caused by GnRH-a, while the treatment of endometriosis is not impaired.