Endometriosis: treatment with gonadotropin-releasing hormone agonist Buserelin

Estrus induction and synchronization in canids and felids

Indications for estrus induction in the dog and cat include potential missed breeding opportunities or conception failure, the treatment of primary or secondary anestrus, out-of-season breeding (feline) and synchronization of ovulation for embryo transfer programs. Reported methods for estrus induction in bitches and queens include the use of synthetic estrogens (diethylstilbesterol), dopamine agonists (bromocriptine and cabergoline), GnRH agonists (lutrelin, buserelin, fertirelin, deslorelin, and leuprolide), exogenous gonadotropins (LH, FSH, hCG, PMSG, and human menopausal gonadotropin) and opiate antagonists (naloxone). These methods vary widely in efficacy of inducing estrus as well as in the fertility of the induced estrus. The applicability of some of these methods for clinical practice is questionable. This review will summarize published reports on estrus induction in canids and felids, both wild and domestic, and provide an update on research using a long-acting injectable deslorelin preparation in bitches.

A case of ovulatory cycle-dependent symptoms in woman with previous interferon beta therapy

A woman with a menstrual cycle-dependent fever (more than 38 degrees C) and severe fatigue that disrupted her ability to work was referred to our hospital. Six years ago, the patient received interferon beta injections (6,000,000 IU day-1x48 days) for the treatment of hepatitis C virus. Although the treatment was successful against the virus, the symptomatic fever occurred monthly since the third year after receiving the treatment. The symptoms occurred a few days after ovulation in every menstrual cycle. When the ovarian function was suppressed by GnRH agonist (GnRHa), the symptoms disappeared. While in anovulation, the patient received estrogen followed by estrogen with progestogen, which resembles the sex hormone milieu of a normal menstrual cycle without the LH surge; this treatment did not induce the symptoms. When human CG (hCG) was injected on the beginning day of estrogen with progestogen following treatment with estrogen alone, the previous symptoms reappeared. However, the hCG injection without estrogen priming did not induce the symptoms. These studies indicated that the LH surge after estrogen priming induced the symptoms. Changes in serum inflammatory cytokine levels (interleukin-1, interleukin-6, and tumor necrosis factor-alpha) were examined during the ovulatory cycle and the interleukin-1 levels during the treatment. There were no significant changes on these levels in the febrile period. The patient experienced normal menstrual cycles after finishing the five-month GnRHa treatment. Although her symptoms still occur, they are mild and do not require further medical treatment.

Medical and surgical therapies for pain associated with endometriosis

Endometriosis is a common condition for which a number of treatments have been proposed. Medical treatments are based on the hormonal responsiveness of endometriosis implants. These therapies include progestins (with or without estrogens), androgens, and gonadotropin-releasing hormone (GnRH) analogs. Surgical treatments may include hysterectomy with oophorectomy or organ-sparing surgery involving ablation or resection of visible lesions of endometriosis and restoration of pelvic anatomy. There are no studies that directly compare the effectiveness or adverse effects of medical therapy and surgical therapy. Studies on medical therapy compare different treatments with placebo or with other active treatments. Hormone-based therapies for endometriosis show 80%-100% effectiveness in relief of pelvic pain over a 6-month course of therapy. Serious adverse outcomes after medical therapy are unusual. Studies on surgical therapy are largely anecdotal, with noncomparative reports on a variety of surgical methods. A few comparative surgical studies have been reported. Because of the noncomparative nature of many of the surgical studies, the use of combinations of surgical procedures and techniques in the reported studies, and the reporting of results from surgeons with an unusually high level of technical skill, the gynecological practitioner has little basis in the literature for assessing the optimum surgical approach. Surgical complications are believed to be underreported and may be related to how aggressive a surgical procedure is undertaken.

Evaluation and management of chronic pelvic pain

Evaluating patients with chronic pelvic pain is complex. A detailed medical history should be ideally supplemented by psychologic evaluation and assessment of the woman's social background. At the time of physical examination, the location and intensity of the pain should be mapped. Assessment of pain relief with the administration of a local anesthetic to trigger points or selected nerves may be useful in predicting the potential efficacy of surgical interventions such as uterosacral nerve ablation. Appropriate tests include pelvic ultrasound and magnetic resonance imaging. Ultimately, laparoscopy may provide the final diagnosis. Management should address the underlying cause(s) of pain; when this cannot be done, it should focus on treating the pain itself. When appropriate, empiric administration of antidepressants may be considered. In selected women, therapeutic goals may be achieved by electrical stimulation of nerves.

Endocrine effects of GnRH analogue with low-dose hormone replacement therapy in women with endometriosis

OBJECTIVE

GnRH analogues are being used increasingly for a number of oestrogen dependent conditions in women. The resultant profound hypo-oestrogenism is a disadvantage, however, but the preservation of pituitary sensitivity to negative feedback by oestradiol is not well defined. We have determined the effect on gonadotrophins and inhibin of GnRH analogue plus low-dose continuous combined hormone replacement therapy in comparison with GnRH analogue therapy alone.

DESIGN

Randomized controlled trial.

PATIENTS

Fifty premenopausal women with endometriosis randomized to treatment with goserelin alone (Group 1) or goserelin plus 17 beta-oestradiol and medroxyprogesterone acetate (Group 2).

MEASUREMENTS

FSH, LH, oestradiol, oestrone, inhibin before and during treatment.

RESULTS

Oestradiol and oestrone were suppressed in both groups, but Group 2 had significantly higher oestradiol during the hormone replacement therapy period. LH was suppressed in both groups. In Group 1, FSH levels recovered during treatment but, in contrast, in Group 2, FSH levels remained suppressed throughout treatment. Inhibin was significantly lower in Group 2, but not in Group 1, during treatment compared to pretreatment.

CONCLUSIONS

Pituitary secretion of FSH appears to remain responsive to feedback control by oestradiol during GnRH analogue therapy and is incompletely suppressed, unlike LH which remains completely suppressed. The possible mechanisms for this are discussed.

The biological basis of medical treatment of endometriosis

Efficacy of medical treatment for the management of endometriosis has been documented in several trials, but clinical results cannot always be maintained after the suspension of treatment. Surgical treatment, either laparotomic or laparoscopic, is affected by up to 20% in the recurrence of clinical symptoms after long-term follow-up. The appearance of endometriosis is heterogeneous, its functional status is variable and could lack hormone responsiveness. After medical, surgical or combined treatment the persistence of the failure of defence mechanisms accounts for the recurrence of disease. Unfortunately, all schemes to classify stages of endometriosis have so far failed to identify manifestations of the disease that respond in a predictable way to specific treatments. An analysis of the morphological appearance, implant biological activity and immune system involvement might better define the roles for medical management of endometriosis.

Pain recurrence: a quality of life issue in endometriosis

Studies reveal endometriosis to be present in 38-51% of women undergoing laparoscopy for chronic pelvic pain. Symptoms attributable to endometriosis include dysmenorrhea, dyspareunia, generalized pelvic pain, dyschezia, and radiation of pain to the back or leg. Psychological factors may also contribute to a more intense pain experience. Medical therapy provides symptom relief in 72-93% of patients, although recurrence is common following treatment discontinuation. Surgical therapy has had varying results for long-term pain relief; adequacy of the initial surgical treatment appears to be a critical factor. Important adjunctive measures include presacral neurectomy and excisional techniques to remove deep, fibrotic, retroperitoneal lesions. The quality of life of women with endometriosis will improve with greater focus on achieving the long-term relief of pelvic pain. Limitation of pain recurrence would benefit the patient greatly, by providing symptom relief and preventing the cycle of its probably adverse effects on physical activity, work productivity, sexual fulfilment, and mood.

A randomized, comparative trial of triptorelin depot (D-Trp6-LHRH) and danazol in the treatment of endometriosis

To compare treatment efficacy and safety parameters a total of 55 premenopausal women with histologically proven endometriosis (stage II-IV) were randomized to receive the LHRH-analogue depot triptorelin (n = 30) or the steroid danazol (n = 25) for a total of 24 weeks. Immediately after cessation of the endocrine therapy a second-look operation was performed. Four as well as 24 weeks after the end of treatment patients were seen for re-evaluation of clinical symptoms and safety parameters. Estradiol suppression was significantly more pronounced with triptorelin, while the free androgenic index rose with danazol. Both substances were equally effective in reducing endometriotic implants (58% and 51%, respectively). Dysmenorrhea was absent at the end of medical therapy in both treatment groups. Dyspareunia and pelvic pain decreased at least by 50%. Red blood count, thrombocytes, liver enzymes and the atherogenic index rose with danazol, while the urinary calcium/creatinine ratio showed a marked elevation with triptorelin. Adverse effects were mainly due to the hypoestrogenism of the LHRH analogue and the androgenic/anabolic properties of the steroid. Triptorelin and danazol are equally effective in treating endometriosis. Therefore, choice of treatment should be based on the patient's medical history and the pharmacological profile of each substance.

Postsurgical medical treatment of advanced endometriosis: results of a randomized clinical trial

OBJECTIVE

Our purpose was to investigate the efficacy of postsurgical treatment with nafarelin in women with advanced endometriosis.

STUDY DESIGN

Eligible for trial were women < or = 38 years old with unexplained infertility with or without chronic pelvic pain and stage III or IV endometriosis according to the American Fertility Society, revised, classification who underwent laparotomy as first surgical treatment for debulking or radical surgery of endometriotic lesions. Patients were assigned according to a randomization list to nasal nafarelin, 400 micrograms/day (36 subjects) or placebo nasal spray (39 subjects) for 3 months. Pelvic pain was assessed before first surgery and at the 12-month follow-up visit in women with pelvic pain by means of a multidimensional score system and a 10-point linear pain scale.

RESULTS

No marked differences in pain scores emerged among women allocated to different treatments. The mean reduction of the multidimensional score was 3.6 and 4.0, respectively, in women allocated to nafarelin and placebo and of the 10-point linear scale scores was 7.0 and 6.9. These differences were not statistically significant. Within 1 year from randomization, of the 36 women allocated to nafarelin and the 39 allocated to placebo, seven (19%) and seven (18%), respectively, became pregnant.

CONCLUSION

This study suggests that medical treatment with nafarelin does not markedly improve pelvic pain and short-term reproductive prognosis in women with stages III and IV endometriosis.

Estrogenic suppression by different administration schedules of goserelin depot for treatment of endometriosis

Eighteen patients affected by laparoscopically confirmed endometriosis were randomly assigned to three different schedules of treatment with gonadotropin-releasing hormone agonist (GnRH-a) (goserelin depot formulation 3.6 mg) every 28 days for 6 months. Six women received the first implant in early follicular phase, 4 in late luteal phase and 8 in 3rd and 17th day from onset of menses. Pretreatment and posttreatment laparoscopic score, performed according to the American Fertility Society scoring system, were compared; a significant reduction in the extent of disease was observed in each group investigated (A and C: p < 0.01; B: p < 0.05). In each treatment group after the second GnRH-a implant the mean levels of estrone-3-glucuronide (E1-3G), daily measured in early morning urine specimens during the control cycle and the first three months of therapy, were suppressed to menopausal women range. In group B during the 2nd and 3rd month of therapy, the urinary mean levels of E1-3G were significantly lower than in group A and C. In conclusion the different goserelin depot administration schedules gave similar laparoscopic improvement, in spite of the first GnRH-a administration in luteal phase allowed a more marked estrogenic suppression.

Buserelin acetate in the treatment of pelvic pain associated with minimal and mild endometriosis: a controlled study

OBJECTIVE

To evaluate the changes of pain symptoms induced by buserelin acetate, a gonadotropin-releasing hormone agonist, in a group of patients with endometriosis.

DESIGN

Thirty-five infertile patients with one or more of the following symptoms (dysmenorrhea, pelvic pain, deep dyspareunia, and endometriosis stage I or II) were allocated randomly to treatment with buserelin acetate 1,200 micrograms/d IN for 6 months (n = 19) or expectant management (n = 16). Pain symptoms were recorded by the women themselves using a questionnaire that included two scales for pain evaluation: one analogue and one multidimensional. The treated and untreated patients were followed for a minimum of 18 and 12 months from the time of randomization, respectively.

RESULTS

Buserelin acetate markedly reduced dysmenorrhea, pelvic pain, and dyspareunia during the treatment and also for the 12 subsequent months. During follow-up of the expectant management group, dysmenorrhea resolved in 19% (3/16) of the cases, and pelvic pain did not recur after diagnostic laparoscopy in one of the three women affected nor did deep dyspareunia in two of the five who reported the symptom before laparoscopy.

CONCLUSION

Buserelin acetate induced a significant improvement of pain symptoms that persisted in approximately half of the patients even after withdrawal of the drug. However, symptoms associated with endometriosis showed a spontaneous remission in approximately one fifth of the untreated patients.

Pemphigoid gestationis--response to chemical oophorectomy with goserelin

A 46-year-old caucasian female presented in January 1991 with a 17-year history of severe pemphigoid gestationis. She had been on systemic steroids for 10 years since her last pregnancy in 1981 and required doses of 20-80 mg prednisolone daily to control her disease. A chemical oophorectomy was induced using a new luteinizing hormone releasing hormone (LHRH) analogue known as goserelin. A complete remission occurred within 6 months of initiating this treatment and the systemic steroids were discontinued.

Tamoxifen in the rat prevents estrogen-deficiency bone loss elicited with the LHRH agonist buserelin

In young women chronic use of luteinizing hormone releasing hormone (LHRH) agonists such as buserelin to treat endometriosis leads to estrogen-deficiency bone loss. Tamoxifen citrate is an estrogen agonist/antagonist which protects the skeleton from osteopenia when ovarian hormones are depleted. The present study was undertaken to determine whether tamoxifen citrate (20 mg/kg body wt/week s.c.) could prevent the osteopenic effect of buserelin (25 micrograms/kg body wt/day s.c.). Four groups of rats with 45Ca-labelled bones were studied for 4 weeks: group A--placebo controls; group B--buserelin; Group C--tamoxifen; group D--buserelin+tamoxifen. Bone resorption was monitored by measuring the urinary excretion of 45Ca and hydroxyproline. Interestingly buserelin lowered both blood 17 beta-estradiol values and uterine weights in the presence and absence of tamoxifen. However, tamoxifen slowed bone breakdown and inhibited the bone-thinning effects of buserelin. Total body calcium values (mg; means +/- S.D.) were: 2227 +/- 137; 1926 +/- 124; 2233 +/- 94 and 2268 +/- 163, in groups A to D respectively. Osteopenia was thus present only in group B (P less than 0.001). Because tamoxifen inhibits estrogen-deficiency bone loss in buserelin-treated rats without depressing the hypoestrogenic actions of this LHRH-agonist, we suggest that use of tamoxifen to protect the skeleton during LHRH-agonist therapy in young women should be explored. Tamoxifen citrate might also help to prevent postmenopausal osteoporosis.

On the origin and significance of serum CA-125 concentrations in 97 patients with endometriosis before, during, and after buserelin acetate, nafarelin, or danazol

OBJECTIVE

To further elucidate the origin and significance of serum CA-125 in pelvic endometriosis.

DESIGN

Retrospective.

PATIENTS

Ninety-seven women with endometriosis who participated in two trials: (1) open-label study on buserelin acetate (n = 51) and (2) comparative, placebo-controlled study on nafarelin (n = 31) versus danazol (n = 15) (2:1 ratio).

INTERVENTIONS

(1) Buserelin acetate 900 micrograms/d intranasally (IN); (2) nafarelin 400 micrograms/d IN versus danazol 400 mg/d orally during 6 months.

MAIN OUTCOME MEASURE(S)

Serum CA-125 and estradiol concentrations; severity of endometriosis-related symptoms; scores according to The American Fertility Society (AFS) classification for endometriosis and/or adhesions (before and on last day of therapy).

RESULTS

Menstruation and adhesions appeared major factors influencing pretreatment serum CA-125 concentrations. Compared with nonmenstruating women without adhesions, both menses and adhesions induced a slight increase tending to significancy, whereas the elevating effect of adhesions and menses together was highly significant and more than expected. All three treatment regimens reduced CA-125 concentrations to the same extent; cessation of therapy was followed by restoration to pretreatment concentrations. Of the AFS scores for implants and/or adhesions, only pretreatment scores for adhesions correlated significantly with CA-125 concentrations. Severity scores for endometriosis-related complaints did not correlate.

CONCLUSIONS

The findings indicate that adhesions play a major role in the presence of CA-125 in the systemic circulation and suggest that reductions of serum CA-125 concentrations during gonadotropin-releasing hormone agonist and danazol therapy are hormonally determined.

Buserelin acetate versus expectant management in the treatment of infertility associated with minimal or mild endometriosis: a randomized clinical trial

OBJECTIVE

We performed a randomized clinical trial to evaluate the efficacy of intranasal 400 micrograms buserelin three times daily for 6 months versus expectant management in the treatment of infertile women with pelvic endometriosis stage I or II of the revised American Fertility Society classification.

STUDY DESIGN

Seventy-one consecutive patients (mean age 32 years) were studied at the First Department of Obstetrics and Gynecology, University of Milan, and the Department of Obstetrics and Gynecology, Ospedali Riuniti, Bergamo, between February 1988 and June 1989. Thirty-five women were randomly allocated to buserelin treatment and 36 to expectant management. The baseline distribution of subjects for age, disease stage, and reproductive history was similar in the two groups. All patients were followed regularly; median follow-up was 17 months in the buserelin group and 18 months in the women given expectant management. If pregnancy did not occur within 12 months of randomization, cycles were monitored by ultrasonography and hormone measurements, and when abnormalities were detected clomiphene citrate and human chorionic gonadotropin were administered.

RESULTS

A total of 17 pregnancies were observed both in the buserelin-treated patients and in the expectant management group. The 1- and 2-year actuarial overall pregnancy rates were similar in the two groups, 30% and 61% in the former and 37% and 61% in the latter group, respectively. Spontaneous abortion occurred in five of the 17 pregnancies in the women treated with buserelin and in one of the 17 in those managed expectantly; this difference was, however, not statistically significant (chi 1(2) adjusted for disease stage and use of clomiphene citrate and human chorionic gonadotropin treatment = 3.01, p = 0.08). No fetal death or stillbirth was observed.

CONCLUSIONS

Our findings suggest that treatment with gonadotropin-releasing hormone agonists is unlikely to have a marked influence on the reproductive outcome of infertile women with minimal or mild endometriosis.

Preventive effects of clomiphene citrate on estrogen-deficiency osteopenia elicited by LHRH agonist administration in the rat

The estrogen agonist and antagonist clomiphene citrate has been shown to prevent bone loss induced by ovariectomy in the rat. In young women estrogen-deficiency bone loss is a clinical problem associated with the use of luteinizing hormone releasing hormone (LHRH) agonists, such as buserelin, to treat endometriosis. The aim of this study was to determine whether clomiphene citrate (10 mg/kg body weight per week orally) would prevent the osteopenic effect of buserelin (25 micrograms/kg body weight per day SC) in the rat. Four groups of animals with 45Ca-labeled skeletons were studied for 4 weeks: group A, placebo controls; group B, buserelin; group C, clomiphene; and group D, buserelin + clomiphene. Bone resorption was monitored by measuring the urinary excretion of 45Ca and hydroxyproline. Clomiphene slowed bone breakdown and inhibited the osteopenic effect of buserelin. Total-body calcium values (mean +/- SD) were (mg) 2635 +/- 181, 2267 +/- 85, 2566 +/- 126, and 2624 +/- 77 in groups A to D, respectively. Osteopenia was present only in group B (P less than 0.001). Interestingly buserelin lowered blood 17 beta-estradiol and uterine weights to a similar extent in the presence and absence of clomiphene. Because clomiphene inhibited estrogen-deficiency bone loss in buserelin-treated rats without depressing the hypoestrogenic action of this LHRH agonist, it is suggested that the use of clomiphene to protect the skeleton during LHRH agonist therapy of endometriosis warrants further study.

Treatment of estrogen-dependent gynecological disorders with the gonadotropin releasing hormone agonist buserelin

The authors examined the effect and tolerability of buserelin in 40 women with endometriosis and ten women with uterine leiomyoma. Buserelin was given intranasally, 200 micrograms three times a day for 6 months. Laparoscopy was performed before and after, and ultrasonography during the treatment. Hormone and lipid profiles and other biochemical tests were run during the treatment. The bone mineral density was tested by dual photon absorptiometry before and after therapy in a group of patients. Although most of the patients complained of hot flushes, no women dropped out. AFS mean pelvic score decreased from 24.10 to 6.95 and the size of the fibroids decreased by 69% at the end of 6 months of treatment. In conclusion, our data suggest that the use of GnRH agonist has a place in the treatment of endometriosis and uterine leiomyoma but further studies are needed to conclude that buserelin given intranasally at a dose of 600 micrograms/day for 6 months is an alternative to other conventional medical treatment modalities in terms of pregnancy and recurrence rates.

17 beta-estradiol protects rats from osteopenia associated with administration of the luteinising hormone releasing hormone (LHRH) agonist, buserelin

Bone loss associated with sustained administration of luteinising hormone releasing hormone (LHRH) agonists, such as buserelin, is attributed to estrogen deficiency. However, the possibility that the LHRH agonists themselves may contribute to the pathogenesis of bone thinning, has not been ruled out. The aim of the present study was to determine whether or not oral 17 beta-estradiol (300 micrograms/kg body wt/week) would fully prevent the osteopenic effect of buserelin (25 micrograms/kg body wt/day s.c.) in the rat. Four groups of animals with 45Ca-labelled skeletons were studied for 4 weeks: group 1, placebo controls; group 2, 17 beta-estradiol; group 3, buserelin; group 4, 17 beta-estradiol + buserelin. Buserelin alone lowered blood estradiol concentrations, increased bone resorption and reduced femur and total body calcium and 45Ca values. Total body calcium values (means +/- SD) were: (mg) 3405 +/- 176; 3250 +/- 282; 2813 +/- 133; 3156 +/- 452 in groups 1 to 4, respectively. Significant osteopenia was present only in group 3 (P less than 0.001). These results support the view that buserelin-mediated bone loss is due to estrogen deficiency. They do not indicate that LHRH agonists per se, play any role in causing bone thinning.

The effect of danazol and the LHRH agonist analogue goserelin (Zoladex) on the biological activity of luteinizing hormone in women with endometriosis

In an attempt to determine whether the suppression in oestradiol levels caused by danazol is due to an effect on the hypothalamic-pituitary axis, we compared the endocrine effects of danazol with those of the LHRH (GnRH) agonist analogue goserelin. Serum levels of immunoreactive LH (I-LH), FSH, 17 beta-oestradiol (E2) and bioactive LH (B-LH) (using a mouse Leydig cell bioassay), were measured in ten and 20 women with endometriosis treated with danazol and goserelin, respectively. I-LH was measured both by radioimmunoassay (RIA) and immunoradiometric assay (IRMA). During 6 months of treatment with 600 mg of danazol daily, mean serum E2 decreased (P less than 0.05) to levels near the upper limit of the post-menopausal range (to a mean (and 95% confidence interval of the mean) of 117 (65-169) pmol/l) whereas FSH, I-LH (both by RIA and IRMA) and B-LH levels were not significantly altered. During 6 months of treatment with monthly depot injections of 3.6 mg goserelin, mean serum E2 decreased (P less than 0.001) to well within the post-menopausal range (to 23 (18-28) pmol/l). The mean FSH, I-LH and B-LH levels also decreased (P less than 0.05) during therapy with goserelin (from 3.9 (3.1-4.7) to 2.0 (1.6-2.4) IU/l for FSH, from 5.3 (4.5-6.1) to 1.9 (1.7-2.1) IU/l for RIA-LH, from 2.9 (2.5-3.3) to less than 0.5 (less than 0.5) IU/l for IRMA-LH and from 9.1 (7.1-11.1) to 2.9 (2.6-3.2) IU/l for B-LH).(ABSTRACT TRUNCATED AT 250 WORDS)

Buserelin. A review of its pharmacodynamic and pharmacokinetic properties, and clinical profile

The gonadotrophin releasing hormone (GnRH) [luteinising hormone-releasing hormone (LHRH); gonadorelin] agonist buserelin is a promising new agent in the treatment of a variety of disorders in gynaecology and andrology, paediatrics and oncology. While a single dose of buserelin stimulates the release of pituitary gonadotrophins, multiple doses produce reversible pituitary desensitisation, and this specific blockade of gonadotrophin support to the gonads provides the basis for the drug's efficacy in conditions dependent on sex hormone secretion. Thus, buserelin provides comparable efficacy to orchidectomy or high dose estrogens in the treatment of hormone-sensitive prostate cancer and exhibits a lower incidence of adverse effects. During the early phase of treatment it may be particularly useful in combination with antiandrogens. Buserelin also appears promising in hormone-sensitive premenopausal breast cancer. Extensive studies have proven the value of buserelin in endometriosis, where it produces a transient remission with gradual recurrence of the disease on cessation of treatment. Surgical intervention is necessary in severe disease after buserelin-induced involution of the lesions. In patients with uterine leiomyoma, preliminary data suggest that buserelin may be beneficial in rendering surgery more conservative by reducing fibroid size, although it appears unlikely to preclude surgical intervention. The use of buserelin to induce a state of reversible hypogonadotrophism before administration of exogenous gonadotrophins is a promising strategy in the treatment of infertility associated with polycystic ovary syndrome and other conditions of infertility with underlying ovarian dysfunction; such a strategy also clearly enhances the efficiency of in vitro fertilisation programmes. Initial studies suggest its potential usefulness as a female contraceptive when administered intermittently in conjunction with a progestogen. Buserelin represents a first-line treatment of central precocious puberty. In endometriosis the adverse effect profile of buserelin is generally favourable, with hypoestrogenic effects such as hot flushes and vaginal dryness, and decreased libido, predominating. There is no apparent detrimental effect on lipid metabolism. The potential for adverse hypoestrogenic effects on bone mineral content with long term administration remains to be clarified. Thus, the GnRH agonist buserelin represents an advance in the treatment of a variety of gynaecological and andrological as well as paediatric and oncological conditions, infertility and other sex-hormone dependent conditions, with a low incidence of adverse treatment effects.

Nafarelin versus danazol in the treatment of endometriosis

A double-blind, double-dummy, 6-month multicenter study comparing the effects of nafarelin and danazol in the treatment of endometriosis was completed recently by investigators from 13 institutions in seven European countries. The 194 patients (aged 18 to 45 years) selected for the study were divided into two groups. One group received nafarelin, 200 micrograms twice daily, and placebo capsules identical to danazol, twice daily. The other group received danazol capsules, 200 mg twice daily, and a placebo nasal spray identical to nafarelin, twice daily. A comparison of decreases in both groups of American Fertility Society endometriosis scores and in severity scores developed by the investigators indicates that nafarelin and danazol are equally effective in the treatment of endometriosis.

Gonadotropin-releasing hormone analogs in the treatment of endometriomas

A limited number of small studies have assessed the efficacy of gonadotropin-releasing hormone agonists in the treatment of ovarian endometriomas. Most of these trials have not used quantitative measurements to evaluate the effects of therapy on disease resolution. The results available thus far suggest that nafarelin, buserelin, and histrelin offer modest degrees of efficacy, similar to that of danazol, in the management of patients with ovarian endometriotic cysts. Gonadotropin-releasing hormone agonists appear to be most efficacious when endometriomas are less than 1 cm in size.