Danazol: endocrine consequences in healthy women

Medical management of endometriosis

INTRODUCTION

Endometriosis is a benign gynecologic disorder that is defined as functional endometrial tissue outside of the uterine cavity. It is an estrogen-dependent, inflammatory disease that leads to symptoms of pelvic pain, dysmenorrhea, dyspareunia, and infertility, occurring in 6-10% of reproductive aged women. The severity of the disease ranges from asymptomatic to debilitating symptoms that have a major impact on women's lives. It is a chronic, recurrent disease, frequently requiring long term management until menopause and beyond. It is considered a chronic disorder that is managed with surgery, medical treatment, and oftentimes, both. Current medical therapy for endometriosis is considered suppressive of the disease, rather than curative. Fortunately, many patients do experience improvement and control of their symptoms with medical therapy. However, long-term efficacy of the medical treatments is often limited by side effects and the cost of therapy, and symptoms do tend to recur after discontinuation of these medications.

AREAS COVERED

This review summarizes our understanding of the pathogenesis of endometriosis and provides more in-depth discussion of specific medical management options used to treat endometriosis, including mechanism of action and side effects. It also provides recommendations on strategy with a forward look to novel endometriosis treatments in the future.

EXPERT OPINION

The authors emphasize that endometriosis is a chronic disorder requiring long term medical therapy. Early diagnosis of endometriosis is key in preventing severe, debilitating symptoms and progression of disease. By utilizing our current knowledge of the pathophysiology of endometriosis and by correctly implementing currently available medical and surgical therapies we can significantly reduce the physical, psychosocial and financial burden of this chronic, recurrent and indolent disease. Current available medications are suppressive therapies, but the authors are looking forward to future therapies that can effectively cure or at least control endometriosis with minimal side effects. Future research should continue to look for the genetic trigger for endometriosis which can lead us to its underlying pathogenesis and eventually a cure or prevention.

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.

Danazol influences gonadotropin secretion acting at the hypothalamic level

OBJECTIVES

The purpose of the study was to determine the influence of danazol on gonadotropin secretion.

METHODS

Ten endometriotic patients were treated with danazol for 6 months. To evaluate gonadotropin and estradiol secretion, a gonadotropin-releasing hormone (GnRH) test and a clomiphene citrate (CC) challenge test were carried out in the follicular phase before treatment, during the sixth month of treatment and after the reappearance of the second menses. The same tests were also performed, only once, in the follicular phase of ten normal women.

RESULTS

GnRH-stimulated gonadotropin response during danazol treatment was significantly higher than that in the same group of women before and after danazol treatment, as well as in controls. Gonadotropin increase after clomiphene citrate administration during danazol treatment was not significant; moreover, LH response was significantly lower than that in the same group of patients before and after danazol treatment, as well as in controls.

CONCLUSIONS

Our results suggest that danazol exerts a suppressive effect on gonadotropin secretion acting at the hypothalamic level.

Danazol in autoimmune haemolytic anaemia

Ten adult patients with warm antibody haemolytic anaemia at initial presentation and seven other patients with either refractory AIHA (two patients) or who relapsed after an initial response to prednisone (five patients) were treated with both Danazol and prednisone. 80% of the first group, but also 60% of the second group displayed long-lasting responses (mean follow up 21 months). Minimal side-effects occurred. Finally, addition of Danazol at presentation in warm AIHA may decrease the duration of prednisone therapy and markedly reduce the necessity of second-line splenectomy which is usually required in many patients.

Thermoregulatory and endocrine effects of a low dose of danazol in postmenopausal women: interaction with the effect of naloxone

Before and on the 30th day of danazol administration (200 mg/day), in six postmenopausal women the activity of endogenous opioid peptides has been indirectly evaluated by the effect on LH secretion and body temperature (measured as rectal temperature) exerted by the infusion of the opioid antagonist naloxone (1.6 mg/h x 4 h preceded by 1.6 mg iv bolus). Before and during danazol administration a GnRH test (100 mcg iv bolus) was also performed to evaluate possible variations in pituitary responsiveness to GnRH. Danazol significantly reduced mean plasma levels of LH and FSH (p less than 0.01), and their response to GnRH stimulus (p less than 0.05). Either before or during danazol administration mean plasma LH and FSH levels did not vary during the infusion of naloxone, while body temperature significantly decreased (p less than 0.01). The decrease in body temperature was significantly greater (p less than 0.05) during danazol than before treatment. The present data suggest that in postmenopausal women a low dose of danazol exerts an antigonadotropic effect mainly reducing the pituitary responsiveness to GnRH. The enhanced hypothermic response to naloxone observed during danazol administration also seems to suggest that in postmenopausal women a low dose of danazol enhances the thermoregulatory role of endogenous opioid peptides.

Endocrine, metabolic, and clinical effects of gestrinone in women with endometriosis

The effect of oral gestrinone, 2.5 mg twice weekly for 6 months, was studied in 11 women with mild or moderate endometriosis laparoscopically confirmed. The mean laparoscopic score decreased from 17.18 to 9.09 (P greater than 0.005). Painful symptoms were relieved in all patients within 2 months from start of therapy. Gonadotropins, prolactin (PRL) 17 beta-estradiol (17 beta-E2), estrone (E1), progesterone (P), androstenedione (A), and dehydroepiandrosterone sulfate (DHEA-S) remained in the follicular phase range. Total testosterone (TT) and sex hormone-binding globulin (SHBG) decreased, whereas free testosterone (FT) slightly increased. Metabolic studies showed a decrease of total triglycerides, very low-density lipoprotein (VLDL) triglycerides, and high-density lipoprotein (HDL) and VLDL cholesterol, parallel to the decrease of associated apoproteins. Low-density lipoprotein cholesterol and apoprotein B increased during therapy. The results suggest that gestrinone possesses antiestrogenic, androgenic, and progestigenic effects at therapeutic dosages both by acting on central and peripheral steroid receptors. For its efficacy and good tolerance, gestrinone may be considered an option for treating endometriosis.

Prolactin and its response to the luteinizing hormone-releasing hormone thyrotropin-releasing hormone test in patients with endometriosis before, during, and after treatment with danazol

Basal levels of prolactin (PRL) were studied in 16 normal women and in 60 women with endometriosis, 37 of whom were infertile. In addition, the authors studied the response to an intravenous (IV) injection of luteinizing hormone-releasing hormone (LH-RH) (100 micrograms) plus thyrotropin-releasing hormone (TRH) (300 micrograms) in the 16 normal women and in 18 endometriosis patients, examining the basal PRL and thyrotropin, and at 15, 30, 45, 60, and 120 minutes after the IV bolus. After laparoscopy and/or conservative surgery, the patients were treated with danazol for 6 months and a second laparoscopy was performed. The LH-RH/TRH test was carried out in the third month of danazol treatment in 6 endometriosis patients and before the second laparoscopy in 11 patients. The results show that there was both an increase in the mean basal levels of PRL and in the percentage of cases of moderate hyperprolactinemia in endometriosis patients. There also was a greater rise in PRL with the LH-RH/TRH test in moderate and severe endometriosis. The PRL response was significantly greater in endometriosis than in normal women, and was not related to TSH response. Danazol treatment reduced significantly the PRL response. The PRL response before treatment was significantly higher in patients who after treatment showed persistent endometriosis at the second laparoscopy. This could suggest a lower effectiveness of danazol in patients with endometriosis and a PRL hyper-response to LH-RH/TRH.

Dosage-related effects of danazol on sex hormone binding globulin and free and total androgen levels

Danazol is known to cause marked suppression of sex hormone binding globulin (SHBG) levels in plasma and to increase the proportion of plasma testosterone unbound to protein but the effect on the concentration of total and free testosterone is unclear. Twenty-five patients with endometriosis were treated daily for 6 months with doses of danazol ranging from 50 to 600 mg. The fall in SHBG and rise in percent free testosterone was dose-related during the early part of treatment. Suppression of total testosterone and 5 alpha-dihydrotestosterone levels occurred and was probably due to increases in metabolic clearance rates. The observed fall in androstenedione levels was related to the incidence of menstrual abnormality, suggesting that this might be due to reduced ovarian activity. The concentration of free testosterone increased by a factor of two in the first week but subsequently returned to levels of between 25 and 50% above pretreatment levels. This pattern of changes may be due to the rise in metabolic clearance rates being dependent on induction of enzymes of androgen metabolism.

Endocrine consequences of danazol treatment in menorrhagia

In order to study the endocrine side-effects of danazol, 15 patients with severe, benign menorrhagias, were individually treated with this drug to stop bleeding. LH, FSH, testosterone, free testosterone, DES-S, androstenedione, prolactin, estradiol and cortisol serum concentrations were measured before and after the 3 month treatment period. Danazol was found to be effective in reducing the amount of bleeding in patients with benign, severe menorrhagias; however, the weight gain of patients was significant during the 3 month period. LH and estradiol concentrations decreased; testosterone, free testosterone and dehydroepiandrosterone sulfate increased; prolactin, FSH, androstenedione and cortisol serum concentrations did not change, and SHBG disappeared from the serum, during the treatment period. We are of the opinion that danazol is an effective drug in menorrhagias with side-effects. In our view the hyperandrogenicity is the most important side-effect of this substance, which might be the result of some metabolites, but which might be the effect of a peripheral action of the drug as well.

Endometriosis

Endometriosis is a common disease associated with pelvic pain and infertility. The etiology and physiology are poorly understood, often frustrating clinicians and patient. Treatment may be medical or surgical, or a combination of these. Nursing care involves education of couples about endometriosis and its physical and psychological implications.

Serum estradiol and danazol. I. Endometriosis response, side effects, administration interval, concurrent spironolactone and dexamethasone

Serum estradiol (E2) levels and resolution of endometriosis were evaluated in 42 women after 75 days of danazol treatment. Complete or almost complete remission occurred when radioimmunoassay E2 levels were less than 15 pg/ml in extensive, less than 22 pg/ml in severe, and less than 41 pg/ml in moderate endometriosis. E2 less than or equal to 20 pg/ml occurred in 23% of 104 patients given 400 mg every 12 hours but in none weighing over 150 pounds (68 kg). E2 greater than 100 pg/ml occurred in 7%. The mean E2 levels were identical with 400 mg every 12 hours and 200 mg every 8 hours. The E2 level was 40% lower with 200 mg every 6 hours than with 400 mg every 12 hours (P less than 0.001). Dexamethasone further decreased E2 levels by 61% (P less than 0.001). Spironolactone decreased androgen symptoms but increased E2 levels by 49% (P less than 0.01).

Profound alterations of the lipoprotein metabolism during danazol treatment in premenopausal women

Twelve women with pelvic endometriosis were treated with 600 mg of danazol daily for 24 weeks. The molar and fractional lecithin:cholesterol acyl transfer (LCAT) rates and the concentrations of cholesterol, phospholipids, and triglycerides were determined in plasma and in the very low-density lipoprotein, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and HDL2 and HDL3 fractions before, during, and after the medication. After 2 weeks the HDL, HDL2, and HDL3 cholesterol concentrations were reduced by 49%, 73%, and 29%, respectively, while the LDL level was increased by 14%. The molar and fractional LCAT rates decreased during treatment, and these reduced LCAT rates are consistent with a reduced fractional LDL removal. Within 8 weeks after cessation of medication, all parameters had returned to the pretreatment levels.

Endocrine effects of danazol in the treatment of endometriosis

The effects of danazol therapy on circulating gonadotrophins, oestradiol and sex hormone-binding globulin (SHBG) binding capacity have been studied in eight patients with endometriosis. There was a significant rise in luteinizing hormone (LH) in the first week of treatment with a fall in oestradiol levels. There was a marked fall in SHBG in the first week which continued up to 4 weeks. It is concluded that danazol is not 'anti-gonadotrophic' as frequently claimed and that its therapeutic actions, side effects and the endocrine changes could be explained by an effect on SHBG production. The rationale of its use in other conditions requires reconsideration.

The effect of danazol on gonadotropin secretion during the follicular phase of the menstrual cycle

The effects of danazol on pulsatile luteinizing hormone (LH) release, basal LH and follicle-stimulating hormone serum levels, gonadotropin release induced by estradiol (E2) and gonadotropin-releasing hormone were examined in five eugonadal women. Danazol administration resulted in a significant suppression of follicle-stimulating hormone serum levels. LH concentrations and LH pulse frequency appeared to be reduced, but these changes did not reach statistical significance. The pituitary response to exogenous gonadotropin-releasing hormone was not altered. The stimulatory effect of E2 on LH secretion was completely abolished in one subject, severely diminished in three subjects, and unchanged in one subject. In addition, the time course of this response was altered. Serum prolactin concentrations were lowered, whereas basal E2 and progesterone levels did not seem to be affected.

Effects of danazol on plasma lipid and lipoprotein levels in healthy women and in women with endometriosis

Previous studies of the effects of danazol on lipid and lipoprotein levels have been conflicting and limited to women with endometriosis. In the present study, plasma levels of lipids and lipoprotein-cholesterol and triglycerides were determined in 25 infertile women with endometriosis and in eight normal women before, during, and after treatment with danazol at daily doses of 200 to 800 mg for 2 to 6 months. Pretreatment values of cholesterol, triglycerides, and lipoprotein were within the normal range in all subjects except three (one with type III and two with type IV hyperlipoproteinemia). During treatment, the mean levels of total cholesterol and triglycerides decreased slightly, while no significant changes in low-density and very low-density lipoproteins were seen. However, a marked (40%) reduction in the mean levels of high-density lipoprotein cholesterol and triglycerides occurred (P less than 0.001) within 4 weeks of therapy in all subjects, which persisted for the duration of the treatment. Patients with pretreatment hyperlipoproteinemia experienced a substantial fall in plasma lipids and lipoprotein and had normal lipoprotein profiles during treatment. Within 4 weeks after danazol was discontinued, all changes in plasma lipid and lipoprotein levels returned to pretreatment levels. These findings have important implications for the atherogenic potential of danazol, a new treatment for hyperlipidemia, and the relationship between gonadal hormones and lipoprotein levels.