Very low dose danazol for relief of endometriosis-associated pelvic pain: a pilot study**Presented at the Conjoint Annual Meeting of The American Fertility Society and The Canadian Fertility and Andrology Society, Montreal, Quebec, Canada, October 11 to 14, 1993

Comparative Analysis of Medical Interventions to Alleviate Endometriosis-Related Pain: A Systematic Review and Network Meta-Analysis

Background/Objectives: Endometriosis is a chronic condition that affects 6-10% of women of reproductive age, with pain and infertility being its primary symptoms. The most common aspects of pain are overall pelvic pain, dysmenorrhea, and dyspareunia. Our aim was to compare the available medical treatments for endometriosis-related pain. Methods: A systematic search was conducted in three medical databases to assess available drug options for pain management. Randomized controlled trials (RCTs) investigating various medical treatments for endometriosis-related pain on different pain scales were included. Results were presented as p-scores and, in cases of placebo controls, as mean differences (MD) with 95% confidence intervals (CI). From the available data, a network meta-analysis was carried out. Results: The search yielded 1314 records, of which 45 were eligible for data extraction. Eight networks were created, and a total of 16 treatments were analyzed. The highest p-score, meaning greatest pain relief (p-score: 0.618), for the treatment of dysmenorrhea was achieved using gonadotropin-releasing hormone (GnRH) agonists for 3 months on a scale of 0-100. Additionally, a p-score of 0.649 was attained following a 6-month treatment with GnRH agonists combined with hormonal contraceptives (CHCs). In the case of dyspareunia on a scale of 0-100 following 3 months of treatment, CHCs (p-score: 0.805) were the most effective, and CHCs combined with aromatase inhibitors (p-score: 0.677) were the best treatment option following 6 months of treatment. In the case of overall pelvic pain, CHCs (p-score: 0.751) yielded the highest p-score on a scale of 0-100 following 3 months of treatment, and progestins combined with aromatase inhibitors (p-score: 0.873) following 6 months of treatment. Progestins (p-score: 0.901) were most effective in cases of overall pelvic pain on a scale of 0-3 following 3 months of treatment. Conclusions: Our network meta-analysis showed that in cases of dysmenorrhea, GnRH agonists supplemented with CHCs reduced pain the most following 3 months of treatment. Regarding dyspareunia CHCs were most effective, and in the case of overall pelvic pain, CHCs or progestins combined with aromatase inhibitors yielded the most desirable results.

A systematic literature review on patient-reported outcome domains and measures in nonsurgical efficacy trials related to chronic pain associated with endometriosis: an urgent call to action

ABSTRACT

Endometriosis, a common cause for chronic pelvic pain, significantly affects quality of life, fertility, and overall productivity of those affected. Therapeutic options remain limited, and collating evidence on treatment efficacy is complicated. One reason could be the heterogeneity of assessed outcomes in nonsurgical clinical trials, impeding meaningful result comparisons. This systematic literature review examines outcome domains and patient-reported outcome measures (PROMs) used in clinical trials. Through comprehensive search of Embase, MEDLINE, and CENTRAL up until July 2022, we screened 1286 records, of which 191 were included in our analyses. Methodological quality (GRADE criteria), information about publication, patient population, and intervention were assessed, and domains as well as PROMs were extracted and analyzed. In accordance with IMMPACT domain framework, the domain pain was assessed in almost all studies (98.4%), followed by adverse events (73.8%). By contrast, assessment of physical functioning (29.8%), improvement and satisfaction (14.1%), and emotional functioning (6.8%) occurred less frequently. Studies of a better methodological quality tended to use more different domains. Nevertheless, combinations of more than 2 domains were rare, failing to comprehensively capture the bio-psycho-social aspects of endometriosis-associated pain. The PROMs used showed an even broader heterogeneity across all studies. Our findings underscore the large heterogeneity of assessed domains and PROMs in clinical pain-related endometriosis trials. This highlights the urgent need for a standardized approach to both, assessed domains and high-quality PROMs ideally realized through development and implementation of a core outcome set, encompassing the most pivotal domains and PROMs for both, stakeholders and patients.

Gonadotropin-releasing hormone analogues for endometriosis

BACKGROUND

Endometriosis is a common gynaecological condition affecting 6 to 11% of reproductive-age women and may cause dyspareunia, dysmenorrhoea, and infertility. One treatment strategy is medical therapy with gonadotrophin-releasing hormone analogues (GnRHas) to reduce pain due to endometriosis. One of the adverse effects of GnRHas is a decreased bone mineral density. In addition to assessing the effect on pain, quality of life, most troublesome symptom and patients' satisfaction, the current review also evaluated the effect on bone mineral density and risk of adverse effects in women with endometriosis who use GnRHas versus other treatment options.

OBJECTIVES

To assess the effectiveness and safety of GnRH analogues (GnRHas) in the treatment of painful symptoms associated with endometriosis and to determine the effects of GnRHas on bone mineral density of women with endometriosis.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase, PsycINFO and the trial registries in May 2022 together with reference checking and contact with study authors and experts in the field to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) which compared GnRHas with other hormonal treatment options, including analgesics, danazol, intra-uterine progestogens, oral or injectable progestogens, gestrinone and also GnRHas compared with no treatment or placebo. Trials comparing GnRHas versus GnRHas in conjunction with add-back therapy (hormonal or non-hormonal) or calcium-regulation agents were also included in this review.  DATA COLLECTION AND ANALYSIS: We used standard methodology as recommended by Cochrane. Primary outcomes are relief of overall pain and the objective measurement of bone mineral density. Secondary outcomes include adverse effects, quality of life, improvement in the most troublesome symptoms and patient satisfaction.  Due to high risk of bias associated with some of the studies, primary analyses of all review outcomes were restricted to studies at low risk of selection bias. Sensitivity analysis including all studies was then performed.

MAIN RESULTS

Seventy-two studies involving 7355 patients were included. The evidence was very low to low quality: the main limitations of all studies were serious risk of bias due to poor reporting of study methods, and serious imprecision.  Trials comparing GnRHas versus no treatment  We did not identify any studies. Trials comparing GnRHas versus placebo There may be a decrease in overall pain, reported as pelvic pain scores (RR 2.14; 95% CI 1.41 to 3.24, 1 RCT, n = 87, low-certainty evidence), dysmenorrhoea scores (RR 2.25; 95% CI 1.59 to 3.16, 1 RCT, n = 85, low-certainty evidence), dyspareunia scores (RR 2.21; 95% CI 1.39 to 3.54, 1 RCT, n = 59, low-certainty evidence), and pelvic tenderness scores (RR 2.28; 95% CI 1.48 to 3.50, 1 RCT, n = 85, low-certainty evidence) after three months of treatment. We are uncertain of the effect for pelvic induration, based on the results found after three months of treatment (RR 1.07; 95% CI 0.64 to 1.79, 1 RCT, n = 81, low-certainty evidence). Besides, treatment with GnRHas may be associated with a greater incidence of hot flushes at three months of treatment (RR 3.08; 95% CI 1.89 to 5.01, 1 RCT, n = 100, low-certainty evidence). Trials comparing GnRHas versus danazol For overall pain, for women treated with either GnRHas or danazol, a subdivision was made between pelvic tenderness, partly resolved and completely resolved. We are uncertain about the effect on relief of overall pain, when a subdivision was made for overall pain (MD -0.30; 95% CI -1.66 to 1.06, 1 RCT, n = 41, very low-certainty evidence), pelvic pain (MD 0.20; 95% CI -0.26 to 0.66, 1 RCT, n = 41, very low-certainty evidence), dysmenorrhoea (MD 0.10; 95% CI -0.49 to 0.69, 1 RCT, n = 41, very low-certainty evidence), dyspareunia (MD -0.20; 95% CI -0.77 to 0.37, 1 RCT, n = 41, very low-certainty evidence), pelvic induration (MD -0.10; 95% CI -0.59 to 0.39, 1 RCT, n = 41, very low-certainty evidence), and pelvic tenderness (MD -0.20; 95% CI -0.78 to 0.38, 1 RCT, n = 41, very low-certainty evidence) after three months of treatment. For pelvic pain (MD 0.50; 95% CI 0.10 to 0.90, 1 RCT, n = 41, very low-certainty evidence) and pelvic induration (MD 0.70; 95% CI 0.21 to 1.19, 1 RCT, n = 41, very low-certainty evidence), the complaints may decrease slightly after treatment with GnRHas, compared to danazol, for six months of treatment. Trials comparing GnRHas versus analgesics  We did not identify any studies. Trials comparing GnRHas versus intra-uterine progestogens We did not identify any low risk of bias studies. Trials comparing GnRHas versus GnRHas in conjunction with calcium-regulating agents There may be a slight decrease in bone mineral density (BMD) after 12 months treatment with GnRHas, compared to GnRHas in conjunction with calcium-regulating agents for anterior-posterior spine (MD -7.00; 95% CI -7.53 to -6.47, 1 RCT, n = 41, very low-certainty evidence) and lateral spine (MD -12.40; 95% CI -13.31 to -11.49, 1 RCT, n = 41, very low-certainty evidence).  AUTHORS' CONCLUSIONS: For relief of overall pain, there may be a slight decrease in favour of treatment with GnRHas compared to placebo or oral or injectable progestogens. We are uncertain about the effect when comparing GnRHas with danazol, intra-uterine progestogens or gestrinone. For BMD, there may be a slight decrease when women are treated with GnRHas, compared to gestrinone. There was a bigger decrease of BMD in favour of GnRHas, compared to GnRHas in conjunction with calcium-regulating agents. However, there may be a slight increase in adverse effects when women are treated with GnRHas, compared to placebo or gestrinone. Due to a very low to low certainty of the evidence, a wide range of outcome measures and a wide range of outcome measurement instruments, the results should be interpreted with caution.

Danazol

A comprehensive profile of danazol describing the nomenclatures, formulae, elemental composition, appearance, uses and applications is presented. The profile contains the method which was utilized for the preparation of the drug substance and its respective scheme is outlined. The physical characteristics of the drug including the solubility, X-ray powder diffraction pattern, differential scanning calorimetry, thermal behavior and spectroscopic studies are described. The methods which were used for the analysis of the drug substance in bulk drug and/or in pharmaceutical formulations including the compendial, spectrophotometric, electrochemical and the chromatographic methods are reported. The stability, toxicity, pharmacokinetics, bioavailability, drug evaluation and monitoring, comparisons, pharmacology, in addition to several compiled reviews on the drug substance which were involved. Finally, two hundred and seventy-nine references are listed at the end of this profile.

Postoperative desogestrel for pelvic endometriosis-related pain: a randomized controlled trial

OBJECTIVE

To determine the effectiveness of desogestrel for relieving endometriosis-related pain.

METHODS

A double-blinded randomized placebo-controlled trial was conducted in 40 patients who had endometriosis with moderate-to-severe dysmenorrhea or chronic pelvic pain undergoing laparoscopic conservative surgery. After surgery, patients were randomized to desogestrel or placebo group. Outcomes included changes in visual analog scale (VAS) of dysmenorrhea, pelvic pain and dyspareunia, patient satisfaction, and adverse effects.

RESULTS

Forty patients were randomized to desogestrel group (n = 20) and placebo group (n = 20). At month 6, the desogestrel group had significantly lower median VAS of overall pelvic pain, dysmenorrhea and noncyclic pelvic pain. Comparing with the placebo group, the desogestrel group had greater reduction in VAS of overall pain, dysmenorrhea and pelvic pain, but comparable reduction in VAS of dyspareunia. No patient in the desogestrel group but 4 patients in the placebo group still had moderate-to-severe pelvic pain at 6 months postoperatively. The proportion of patients who rated the treatment as very satisfied was higher in the desogestrel group than in the placebo group. There was no serious adverse event during the study period.

CONCLUSIONS

Desogestrel is effective and acceptable for postoperative therapy for patients with moderate-to-severe pain related to endometriosis.

"Per vaginam" topical use of hormonal drugs in women with symptomatic deep endometriosis: a narrative literature review

PURPOSE

We aim to provide a comprehensive overview of the role of the vagina as a route for drug delivery and absorption, with a particular focus on the use of vaginal hormonal compounds for the treatment of deep infiltrating symptomatic endometriosis.

METHODS

A MEDLINE search through PubMed was performed to identify all published studies in English language on vaginal hormonal treatments for symptomatic endometriosis.

RESULTS

Main advantages of the vaginal route include avoidance of the hepatic-first pass metabolic effect, the possibility of using lower therapeutic dosages, and the reduction of side effects compared with the oral administration. Studies on endometriosis treatment mainly focused on the use of vaginal danazol (n = 6) and the contraceptive vaginal ring (n = 2). One pilot study evaluated the efficacy of vaginal anastrozole in women with rectovaginal endometriosis. Most investigations evaluated the vaginal use of hormonal agents in women with deep infiltrating endometriosis/rectovaginal endometriosis. Overall, a substantial amelioration of pelvic pain symptoms associated with endometriosis was observed, particularly of dysmenorrhea. A significant reduction in rectovaginal endometriotic nodule dimensions measured at ultrasound examination was detected by some but not all authors.

CONCLUSIONS

The vaginal route represents a scarcely explored modality for drug administration. High local hormonal concentrations might achieve a greater effect on endometriotic lesions compared with alternative routes. Future studies should focus on the use of the vagina for delivering target therapies particularly in patients with deeply infiltrating rectovaginal lesions.

Gonadotrophin-releasing hormone analogues for pain associated with endometriosis

EDITORIAL NOTE

See https://pubmed.ncbi.nlm.nih.gov/37341141/ for a more recent review that covers this topic and has superseded this review.

BACKGROUND

Endometriosis is a common gynaecological condition, characterised by the presence of endometrial tissue in sites other than the uterine cavity (excluding adenomyosis) that frequently presents with pain. The gonadotrophin-releasing hormone analogues (GnRHas) comprise one intervention that has been offered for pain relief in pre-menopausal women. GnRHas can be administered intranasally, by subcutaneous, or intramuscular injection. They are thought to result in down regulation of the pituitary and induce a hypogonadotrophic hypogonadal state.

OBJECTIVES

To determine the effectiveness and safety of GnRHas in the treatment of the painful symptoms associated with endometriosis.

SEARCH STRATEGY

Electronic searches of the Cochrane Menstrual Disorders and Subfertility Group specialist register, CENTRAL, MEDLINE, EMBASE, PSYCInfo and CINAHL were conducted in April 2010 to identify relevant randomised controlled trials (RCTs).

SELECTION CRITERIA

RCTs of GnRHas as treatment for pain associated with endometriosis versus no treatment, placebo, danazol, intra-uterine progestagens, or other GnRHas were included. Trials using add-back therapy, oral contraceptives, surgical intervention, GnRH antagonists or complementary therapies were excluded.

DATA COLLECTION AND ANALYSIS

Quality assessment and data extraction were performed independently by two reviewers. The primary outcome was pain relief. Relative risk was used as the measure of effect for dichotomous data. For continuous data, mean differences or standardised mean differences were used.

MAIN RESULTS

Forty one trials (n=4935 women) were included. The evidence suggested that GnRHas were more effective at symptom relief than no treatment/placebo. There was no statistically significant difference between GnRHas and danazol for dysmenorrhoea RR 0.98 (95%CI 0.92 to 1.04; P = 0.53). This equates to 3 fewer women per 1000 (95%CI 12 to 6) with symptomatic pain relief in the GnRHa group. More adverse events were reported in the GnRHa group. There was a benefit in overall resolution for GnRHas RR1.10 (95%CI 1.01 to 1.21, P=0.03) compared with danazol. There was no statistically significant difference in overall pain between GnRHas and levonorgestrel SMD -0.25 (95%CI -0.60 to 0.10, P=0.46). Evidence was limited on optimal dosage or duration of treatment for GnRHas. No route of administration appeared superior to another.

AUTHORS' CONCLUSIONS

GnRHas appear to be more effective at relieving pain associated with endometriosis than no treatment/placebo. There was no evidence of a difference in pain relief between GnRHas and danazol although more adverse events reported in the GnRHa groups. There was no evidence of a difference in pain relief between GnRHas and levonorgestrel and no studies compared GnRHas with analgesics.

Current pharmacotherapy for endometriosis

IMPORTANCE OF THE FIELD

Medical therapy is the most commonly used treatment for endometriosis. In particular, the administration of hormonal therapies aims to improve symptoms with minimal adverse effects.

AREAS COVERED IN THIS REVIEW

Observational and randomized studies evaluating the efficacy of medical therapy on symptoms associated with endometriosis were reviewed. We searched Medline, Embase and the Cochrane Library up to December 2009.

WHAT THE READER WILL GAIN

The reader will obtain information on the available medical therapies used to treat endometriosis-related symptoms either after surgery or as an alternative to the surgical excision of endometriosis. The effectiveness of therapies, the dose of drugs, the length of treatment and the adverse effects are examined.

TAKE HOME MESSAGE

Medical therapies can efficaciously reduce the severity of pain symptoms caused by endometriosis. Recurrence of symptoms is common after discontinuation of medical therapies; therefore, the choice of the therapy should be based not only on the improvements of symptoms but also on the potential adverse effects and patients' satisfaction.

Thoracic Endometriosis: Current Knowledge

Thoracic endometriosis syndrome includes four well-recognized clinical entities, namely catamenial pneumothorax, catamenial hemothorax, catamenial hemoptysis and lung nodules, as well as some exceptional presentations. The etiological mechanisms of this syndrome are not well understood, and different theories have been proposed. Controversies exist about optimal management, as experience has been drawn from case reports and small clinical series. Surgery, hormonal treatments and combined approaches have all been proposed, with variable results in terms of short and long term outcome.

Medical management of endometriosis-associated pain

In the coming years, basic science research into the mechanisms of endometriosis development and persistence almost certainly will open new avenues for treatment. A wide armamentarium of medical therapies already exists, however. The efficacy of most of these methods in reducing endometriosis-associated pain is well established. The choice of which to use depends largely on patient preference after an appropriate discussion of risks, side effects, and cost. Typically, oral contraceptives and NSAIDs are first-line therapy because of their low cost and mild side effects (Box 6). Because of its greater potential for suppressing endometrial development, consideration should be given to prescribing a low-dose monophasic oral contraceptive continuously. If adequate relief is not obtained or if side effects prove intolerable, consideration should be given to the use of progestins (oral, intramuscular, or IUD) or a GnRH agonist with immediate add-back therapy. Progestins are less expensive, but GnRH agonists with add-back may be better tolerated. If none of these medications proves beneficial or if side effects are too pronounced, then repeat surgery is warranted. The surgery may have analgesic value and serves to reconfirm the diagnosis. Finally, if endometriosis is identified at the time of surgery, then consideration should be given to prescribing medical therapy postoperatively.

Endometriosis and pain

Endometriosis generally causes pain that is cyclic and generally responds to medication and/or surgery. When endometriosis is found coincidentally, it may need no treatment because many women have endometriosis as a self-limited disease. In other women, the biologic behavior is much more unpredictable. Severe dysmenorrhea, focal pelvic tenderness, and deep dyspareunia are suggestive of endometriosis. Diagnosis at laparoscopy includes concerns about subtle appearance, endometriosis hidden within adhesions, retroperitoneal disease, and intra-ovarian lesions. Negative laparoscopy results do not mean that patients have no endometriosis. In contrast, a response to GnRH agonists can occur in patients with no endometriosis because conditions other than endometriosis are estrogen sensitive. Coexistent disease can confuse the picture at the time of surgery. Some coexistent diseases also can cause pain that is similar to that of endometriosis. Distinguishing those patients who need no treatment from those who need intermediate or extensive treatment can be very difficult. Care is needed to ensure that patients are neither overtreated or undertreated. An integrated approach involving a multidisciplinary team is needed in some. Other patients respond to primary care techniques.

Low-dose danazol after combined surgical and medical therapy reduces the incidence of pelvic pain in women with moderate and severe endometriosis

The most effective therapy for endometriosis is a matter for debate. The aim of the present randomized study was to evaluate the efficacy of low doses of danazol on recurrence of pelvic pain in patients with moderate or severe endometriosis, who had undergone laparoscopic surgery and 6 months of gonadotrophin-releasing hormone analogue (GnRHa) therapy. After surgery, 28 patients with moderate or severe endometriosis underwent therapy for 6 months with GnRHa i. m. every 4 weeks. They were then randomized into two groups: group A (14 subjects) was treated with 100 mg/day danazol for 6 months; group B (14 subjects, control) did not receive any type of therapy. After 12 months of treatment, group A had a significantly (P < 0.01) lower pain score than group B. There was no significant difference between the groups in oestrogen concentrations, bone mineral density or side-effects. The results suggest that low-dose danazol therapy reduces recurrence of pelvic pain in patients with moderate or severe endometriosis, treated surgically, and has few or no metabolic side-effects.

The evidence for the management of endometriosis

This review article has focussed on identifying the evidence from randomized controlled trials for the medical and surgical management of endometriosis. A critical summary of the medical management has shown that there is little difference in effectiveness of various medical treatments, but there are differences in the side-effect profiles. Few randomized controlled trials have been undertaken in surgery, but these have shown that surgical management is effective in the management of both painful symptoms and subfertility.

Progestins for symptomatic endometriosis: a critical analysis of the evidence

OBJECTIVE

To obtain estimates of the effects of progestin treatment for pelvic pain associated with endometriosis.

DATA IDENTIFICATION

Information from studies published in the English-language literature between 1966 and 1996 was pooled. Articles were identified through hand and computerized searches using MEDLINE.

STUDY SELECTION

A total of 27 trials that were published in peer-reviewed journals were identified, and 13 of these were excluded from the analysis because of methodologic limitations. Nine of the remaining 14 studies were noncomparative (8 prospective and 1 retrospective), 1 was quasi-randomized, and 4 were true randomized controlled trials.

DATA EXTRACTION AND SYNTHESIS

The sample size was generally limited; the mean number of patients included was 26 in the noncomparative trials and 29 in the randomized controlled trials. The mean duration of treatment was 6 months. A total of 355 women had pain at entry. Considering all noncomparative studies, the pooled frequency of nonresponders at the end of treatment was 9% (18/203; 95% confidence interval [CI], 5.3% to 13.6%). The common odds ratio from the four randomized controlled trials comparing progestins with danazol or a GnRH agonist was 1.1 (95% CI, 0.4 to 3.1), suggesting equivalence in treatment effect. In the only double-blind, placebo-controlled trial, the frequency of nonresponders was not significantly different in the two arms. Only four studies assessed pain after drug withdrawal. The pooled frequency of pelvic pain at the end of follow-up was 50% (35/70; 95% CI, 37.8% to 62.2%). The overall crude conception rate after therapy among women who desired pregnancy was 44% (86/194; 95% CI, 37.2% to 51.6%). Side effects of limited clinical relevance were observed frequently.

CONCLUSION(S)

The available data suggest that the efficacy of progestins for temporary relief of endometriosis-associated pelvic pain is good and comparable to that of other, less safe treatments.

Depot medroxyprogesterone acetate versus an oral contraceptive combined with very-low-dose danazol for long-term treatment of pelvic pain associated with endometriosis

OBJECTIVE

Our purpose was to evaluate the efficacy and safety of depot medroxyprogesterone acetate versus an oral contraceptive combined with very-low-dose danazol in the long-term treatment of pelvic pain in women with endometriosis.

STUDY DESIGN

Eighty patients with endometriosis and moderate or severe pelvic pain were randomized to treatment for 1 year with intramuscular depot medroxyprogesterone acetate 150 mg every 3 months or a cyclic monophasic oral contraceptive (ethinyl estradiol 0.02 mg, desogestrel 0.15 mg) combined with oral danazol 50 mg a day for 21 days of each 28-day cycle. The women were asked to grade the degree of their satisfaction at the end of therapy. Variations in severity of symptoms during treatment were determined by a 10 cm visual analog and a 0- to 3-point verbal rating scale.

RESULTS

Twenty nine of 40 subjects (72.5%) in the depot medroxyprogesterone acetate group were satisfied after 1 year of therapy compared with 23 of 40 (57.5%) in the oral contraceptive plus danazol group (chi 2(1) = 1.37, p = 0.24, odds ratio 1.95, 95% confidence interval 0.76 to 4.97). A significant decrease was observed in all symptom scores in both study groups. At 1-year assessment dysmenorrhea was significantly greater in women allocated to oral contraceptive plus danazol.

CONCLUSION

Depot medroxyprogesterone acetate seems to be an effective, safe, and convenient low-cost treatment for pelvic pain associated with endometriosis. However, women should be carefully counseled regarding menstrual changes and the potential prolonged delay in the return of ovulation.