Medical treatment of endometriosis: a comparison of the suppressive effects of danazol and nafarelin on reproductive hormones

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.

New treatment strategies and emerging drugs in endometriosis

Introduction: Endometriosis, histologically defined as the presence of endometrium-like tissue - glands and stroma - that develops outside of the uterine cavity, is still an enigmatic disease responsible for pelvic pain and infertility. The current treatments of endometriosis are surgery and hormonal therapies that act by suppressing ovulation and/or directly on steroid receptors located in endometriotic lesions. Areas covered: New hormonal and non-hormonal therapies are being developed for the treatment of endometriosis-related pain. The authors review the state of advancement and the results of novel treatments studied in registered trials ( www.ClinicalTrials.gov ). Cellular signaling pathways activated in endometriotic cells, which constitute potential targets for future treatments, are also described. Expert opinion: Therapeutic research efforts should focus on identifying and testing substances capable of acting locally on the lesions themselves, without interfering with ovulation, in order to be efficacious on both pain symptoms and infertility.

Ovulation suppression for endometriosis

BACKGROUND

Endometriosis is the finding of endometrial glands or stroma in sites other than the uterine cavity. Endometriosis appears to be an oestrogen dependent condition. This hormonal dependency has prompted the therapeutic use of ovulation suppression agents, in an effort to improve subsequent fertility.

OBJECTIVES

To assess the effectiveness of ovulation suppression agents, including danazol, progestins and oral contraceptives, in the treatment of endometriosis-associated subfertility in improving pregnancy outcomes including live birth.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Sub-fertility Group's specialised register of trials (searched October 5th, 2007) the Cochrane Register of Controlled Trials (The Cochrane Library, Issue 3, 2007), MEDLINE (1966-October 2007), EMBASE (1980 - October 2007) and reference lists of articles.

SELECTION CRITERIA

Randomised trials comparing an ovulation suppression agent with placebo or no treatment, or a suppressive agent with danazol or a GnRH with oral contraception in women with endometriosis. A total of twenty three RCTs comparing an ovulation suppression agent with placebo or no treatment, or a suppressive agent with danazol or a GnRH with oral contraception were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed quality. We contacted study authors for additional information. Quality was assessed by of method of randomization,allocation concealment, blinding, completeness of follow-up, presence or absence of crossover and co-intervention. 2 x 2 tables were generated for all relevant outcomes. Odds ratios were generated using the Peto modified Mantel-Haenszel technique. Statistical heterogeneity was assessed using the I(2) test of heterogeneity. Subgroup analysis was conducted on those couples clearly identifiable as infertile or wanting to conceive.

MAIN RESULTS

Twenty four trials were included. The odds ratio for pregnancy following ovulation suppression versus placebo or no treatment for all women randomised was 0.79 (95% CI 0.54 to 1.14), P = 0.21 and 0.80 (95% CI 0.51 to 1.24), P = 0.32 respectively for subfertile couples only despite the use of a variety of suppression agents. There was no evidence of benefit from the treatment. The common odds ratio for pregnancy following all agents versus danazol for all women randomised was 1.38 (95% CI 1.05 to 1.82), P = 0.02 and OR 1.37 (95% CI 0.94 to 1.99), P = 0.10 for subfertile couples only. When GnRHa and danazol were directly compared, OR was 1.45 (95% CI 1.08 to 1.95) P = 0.01 for all women randomised and OR 1.63( 95% CI 1.12 to 2.37), P = 0.01 for subfertile couples only in favour of GnRH. No effect was observed for GnRH compared with oral contraception; OR 0.99 (95% CI 0.52 to 1.89), P = 0.98 for all women randomised and OR 0.79 ( 95% CI 0.37 to 1.69), P = 0.55. In all analyses the data were statistically homogeneous (I(2)=0%).

AUTHORS' CONCLUSIONS

There is no evidence of benefit in the use of ovulation suppression in subfertile women with endometriosis who wish to conceive.

WITHDRAWN: Gonadotrophin-releasing hormone analogues for pain associated with endometriosis

BACKGROUND

Endometriosis is a common gynaecological condition that frequently presents with the symptom of pain. The precise pathogenesis (mode of development) of endometriosis is unclear but it is evident that endometriosis arises by the dissemination of endometrium to ectopic sites and the subsequent establishment of deposits of ectopic endometrium. The observation that endometriosis is rarely seen in the hypo-oestrogenic (low levels of oestrogen) post-menopausal woman led to the concept of medical treatment by induction of a pseudo-menopause using Gonadotrophin Releasing Hormone Analogues (GnRHas). When administered in a non-pulsatile manner (the pituitary is normally stimulated by pulses of natural GnRH and all analogues act on the pituitary at a constant level) their use results in down regulation (switching off) of the pituitary and a hypogonadotrophic hypogonadal state (low levels of female hormones due to non stimulation of the ovary).

OBJECTIVES

To determine the effectiveness of Gonadotrophin Releasing Hormone analogues (GnRHas) in the treatment of the painful symptoms of endometriosis by comparing them with no treatment, placebo, other recognised medical treatments, and surgical interventions.

SEARCH STRATEGY

The search strategy of the Menstrual Disorders and Subfertility review group (please see Review Group details) was used to identify all randomised trials of the use of GnRHas for the treatment of the painful symptoms of endometriosis.

SELECTION CRITERIA

Trials were included if they were randomised, and considered the effectiveness of GnRHas in the treatment of the painful symptoms of endometriosis.

DATA COLLECTION AND ANALYSIS

Twenty-six studies had data appropriate for inclusion in the review. The largest group (15 studies) compared GnRHas with danazol. There are five studies comparing GnRHas with GnRHas plus add-back therapy, three comparing GnRHa with GnRHa in a different form or dose, one compares them with gestrinone, one with the combined oral contraceptive pill, and one with placebo. Data was extracted independently by two reviewers. The authors of eleven studies have been contacted to clarify missing or unclear data. Only four have replied to date. Data on relief of pain, change in revised American Fertility Society (rAFS) scores, and side effects was collected.

MAIN RESULTS

No difference was found between GnRHas and any of the other active comparators with respect to pain relief or reduction in endometriotic deposits. The side effect profiles of the different treatments were different, with danazol and gestrinone having more androgenic side effects, while GnRHas tend to produce more hypo-oestrogenic symptoms.

AUTHORS' CONCLUSIONS

There is little or no difference in the effectiveness of GnRHas in comparison with other medical treatments for endometriosis. GnRHas do appear to be an effective treatment. Differences that do exist relate to side effect profiles. Side effects of GnRHas can be ameliorated by the addition of addback therapy.

Ovulation suppression for endometriosis

BACKGROUND

Endometriosis is the finding of endometrial glands or stroma in sites other than the uterine cavity. Endometriosis appears to be an estrogen dependent condition. This hormonal dependency has prompted the therapeutic use of ovulation suppression agents, in an effort to improve subsequent fertility.

OBJECTIVES

To determine the effectiveness of a) ovulation suppression with danazol, medroxy progesterone acetate, gestrinone, combined oral contraceptive pills and GnRH analogues versus placebo or no treatment and b) any of the above agents versus danazol, for the treatment of endometriosis-associated subfertility.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trial register (searched 30 April 2002), the Cochrane Central Register of Controlled Trials (Cochrane Library, Issue 2, 2002), MEDLINE (January 1966 to December 1998), EMBASE (January 1985 to December 1997) and reference lists of articles. We also contacted manufacturers and researchers in the field.

SELECTION CRITERIA

Trials comparing the interventions described above, were included if allocation to treatment was based on a random process. Six RCTs with seven treatment arms compared an ovulation suppression agent with placebo or no treatment. Ten trials were identified comparing a suppressive agent with danazol.

DATA COLLECTION AND ANALYSIS

Relevant data were extracted independently by two reviewers using the standardised data extraction sheet. Validity was assessed in terms of method of randomisation, completeness of follow-up, presence or absence of crossover and co-intervention. 2 x 2 tables were generated for all relevant outcomes. Odds ratios were generated using the Peto modified Mantel-Haenszel technique. Statistical heterogeneity was assessed using Breslow-Day X2.

MAIN RESULTS

The odds ratio for pregnancy following ovulation suppression versus placebo or no treatment was 0.74 (95%CI 0.48 to 1.15). These data were statistically homogeneous, despite the use of a variety of suppression agents. They suggest no statistically significant benefit from treatment. The odds ratio for pregnancy following all agents versus danazol, the most commonly used agent prior to the advent of gonadotropin releasing hormone agonists (GnRHa), was 1.3 (95% CI 0.97 to 1.76). When GnRHa and danazol were directly compared, the odds ratio for pregnancy across six trials, was similar to the summary statistic for all ten studies: 1.29 (95% CI 0.9 to 1.85). Again, this suggests no statistically significant difference between these interventions.

REVIEWER'S CONCLUSIONS

These results rule out a benefit of more than a 15% increase in odds, and do not justify the risk of side effects when used as therapy for endometriosis-associated subfertility.

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.

Endometriosis: medical therapy

The management of women with endometriosis is complex and necessitates individualization of patient care. The most commonly used medical therapies are danazol, GnRH agonists, medroxyprogesterone acetate and gestrinone. Studies to date have shown these drugs to have equal efficacy in terms of reduction in laparoscopic score and relief of symptoms. However, their side-effects make them unsuitable for long-term use. The addition of low dose hormone replacement therapy to GnRH agonist regimens may allow prolonged use but the current cost of these agents is high. Low dose oral contraceptive pills deserve further investigation. The role of medical treatment for women with endometriosis and infertility is controversial. There is no place for hormonal therapy in such women with stage I or II disease. When expectant management fails, gamete intrafallopian transfer offers excellent results. For those with stage III or IV disease, surgery is preferable with adjunctive medical therapy in selected cases. If pregnancy does not ensue, in vitro fertilization and embryo transfer are the next line of management, and results are optimized by prior medical therapy and aspiration of endometriomas. Major advances have been made in the medical management of endometriosis. However, current treatment strategies are ineffective in eliminating the disease in most women. New approaches are required in both basic and clinical research in order to finally eradicate this often devastating disease.