Review: The mechanism of action of danazol, a novel steroid derivative

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.

Danazol alters mitochondria metabolism of fibrocystic breast Mcf10A cells

Fibrocystic Breast Disease (FBD) or Fibrocystic change (FC) affects about 60% of women at some time during their life. Although usually benign, it is often associated with pain and tenderness (mastalgia). The synthetic steroid danazol has been shown to be effective in reducing the pain associated with FBD, but the cellular and molecular mechanisms for its action have not been elucidated. We investigated the hypothesis that danazol acts by affecting energy metabolism. Effects of danazol on Mcf10A cells homeostasis, including mechanisms of oxidative phosphorylation, cytosolic calcium signaling and oxidative stress, were assessed by high-resolution respirometry and flow cytometry. In addition to fast physiological responses the associated genomic modulations were evaluated by Affimetrix microarray analysis. The alterations of mitochondria membrane potential and respiratory activity, downregulation of energy metabolism transcripts result in suppression of energy homeostasis and arrest of Mcf10A cells growth. The data obtained in this study impacts the recognition of direct control of mitochondria by cellular mechanisms associated with altered energy metabolism genes governing the breast tissue susceptibility and response to medication by danazol.

Non-surgical interventions for treating heavy menstrual bleeding (menorrhagia) in women with bleeding disorders

BACKGROUND

Heavy menstrual bleeding without an organic lesion is mainly due to an imbalance of the various hormones which have a regulatory effect on the menstrual cycle. Another cause of heavy menstrual bleeding with no pelvic pathology, is the presence of an acquired or inherited bleeding disorder. The haemostatic system has a central role in controlling the amount and the duration of menstrual bleeding, thus abnormally prolonged or profuse bleeding does occur in most women affected by bleeding disorders. Whereas irregular, pre-menarchal or post-menopausal uterine bleeding is unusual in inherited or acquired haemorrhagic disorders, severe acute bleeding and heavy menstrual bleeding at menarche and chronic heavy menstrual bleeding during the entire reproductive life are common. This is an update of a previously published Cochrane Review.

OBJECTIVES

To determine the efficacy and safety of non-surgical interventions versus each other, placebo or no treatment for reducing menstrual blood loss in women with bleeding disorders.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Haemoglobinopathies Trials Register (25 August 2016), Embase (May 2013), LILACS (February 2013) and the WHO International Clinical Trial registry (February 2013).

SELECTION CRITERIA

Randomised controlled studies of non-surgical interventions for treating heavy menstrual bleeding (menorrhagia) in women of reproductive age suffering from a congenital or acquired bleeding disorder.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion, extracted data and assessed the risk of bias.

MAIN RESULTS

Three cross-over studies, with 175 women were included in the review. All three studies had an unclear risk of bias with regards to trial design and overall, the quality of evidence generated was judged to be poor.Two of the studies (n = 59) compared desmopressin (1-deamino-8-D-arginine vasopressin) with placebo. Menstrual blood loss was the primary outcome for both of these studies. Neither study found clear evidence of a difference between groups. The first of these reported a mean difference in menstrual blood loss in the desmopressin versus placebo group of 21.20 mL (95% confidence interval -19.00 to 61.50)The second study reported that even though there was an improvement of pictorial bleeding assessment chart scores with desmopressin and placebo when compared to pretreatment assessment, there was no clear evidence of difference in these scores when the two were compared to each other (results presented graphically, P = 0.51). The data from these studies could not be combined.The third study (n = 116) compared desmopressin with tranexamic acid (n = 116). This study found a decrease in pictorial bleeding assessment chart scores after both treatments as compared to baseline. The decrease in these scores was greater for tranexamic acid than for desmopressin, with a mean difference of 41.6 mL (95% confidence interval 19.6 to 63) (P < 0.0002).In relation to adverse events, across two studies, there was no clear evidence of a difference when placebo was compared to desmopressin, risk ratio 1.17 (95% confidence interval 0.41 to 3.34) . The same was also true when desmopressin was compared to tranexamic acid, risk ratio 1.17 (95% confidence interval 0.41 to 3.34).Only the study that compared desmopressin to tranexamic acid assessed quality of life. However, we are unable to present any data from this study, since no differences in this outcome between the two intervention groups were reported.

AUTHORS' CONCLUSIONS

Evidence from randomised controlled studies on the effect of desmopressin when compared to placebo in reducing menstrual blood loss is very limited and inconclusive. Two studies, each with a very limited number of participants, have shown uncertain effects in menstrual blood loss and adverse effects. A non-randomised comparison in one of the studies points to the value of combining desmopressin and tranexamic acid, which needs to be tested in a formal randomised controlled study comparison.When tranexamic acid was compared to desmopressin, a single study showed a reduction in menstrual blood loss with tranexamic acid use compared to desmopressin.There is a need to evaluate non-surgical methods for treating of menorrhagia in women with bleeding disorders through randomised controlled studies. Such methods would be more acceptable than surgery for women wishing to retain their fertility. Given that women may need to use these treatments throughout their entire reproductive life, long-term side-effects should be evaluated.

Non-surgical interventions for treating heavy menstrual bleeding (menorrhagia) in women with bleeding disorders

BACKGROUND

Heavy menstrual bleeding without an organic lesion is mainly due to an imbalance of the various hormones which have a regulatory effect on the menstrual cycle. Another cause of heavy menstrual bleeding with no pelvic pathology, is the presence of an acquired or inherited bleeding disorder. The haemostatic system has a central role in controlling the amount and the duration of menstrual bleeding, thus abnormally prolonged or profuse bleeding does occur in most women affected by bleeding disorders. Whereas irregular, pre-menarchal or post-menopausal uterine bleeding is unusual in inherited or acquired haemorrhagic disorders, severe acute bleeding and heavy menstrual bleeding at menarche and chronic heavy menstrual bleeding during the entire reproductive life are common.

OBJECTIVES

To determine the efficacy and safety of non-surgical interventions versus each other, placebo or no treatment for reducing menstrual blood loss in women with bleeding disorders.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Haemoglobinopathies Trials Register (13 March 2014), Embase (May 2013), LILACS (February 2013) and the WHO International Clinical Trial registry (February 2013).

SELECTION CRITERIA

Randomised controlled studies of non-surgical interventions for treating heavy menstrual bleeding (menorrhagia) in women of reproductive age suffering from a congenital or acquired bleeding disorder.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion, extracted data and assessed the risk of bias.

MAIN RESULTS

Three cross-over studies, with 175 participants were included in the review. All three studies had an unclear risk of bias with regards to trial design and overall, the quality of evidence generated was judged to be poor.Two of the studies (n = 59) compared desmopressin (1-deamino-8-D-arginine vasopressin) with placebo. Menstrual blood loss was the primary outcome for both of these studies. Neither study found clear evidence of a difference between groups. The first of these reported a mean difference in menstrual blood loss in the desmopressin versus placebo group of 21.20 mL (95% confidence interval -19.00 to 61.50)The second study reported that even though there was an improvement of pictorial bleeding assessment chart scores with desmopressin and placebo when compared to pretreatment assessment, there was no clear evidence of difference in these scores when the two were compared to each other (results presented graphically, P = 0.51). The data from these studies could not be combined.The third study (n = 116) compared desmopressin with tranexamic acid (n = 116). This study found a decrease in pictorial bleeding assessment chart scores after both treatments as compared to baseline. The decrease in these scores was greater for tranexamic acid than for desmopressin, with a mean difference of 41.6 mL (95% confidence interval 19.6 to 63) (P < 0.0002).In relation to adverse events, across two studies, there was no clear evidence of a difference when placebo was compared to desmopressin, risk ratio 1.17 (95% confidence interval 0.41 to 3.34) . The same was also true when desmopressin was compared to tranexamic acid, risk ratio 1.17 (95% confidence interval 0.41 to 3.34).Only the study that compared desmopressin to tranexamic acid assessed quality of life. However, we are unable to present any data from this study, since no differences in this outcome between the two intervention groups were reported.

AUTHORS' CONCLUSIONS

Evidence from randomised controlled studies on the effect of desmopressin when compared to placebo in reducing menstrual blood loss is very limited and inconclusive. Two studies, each with a very limited number of participants, have shown uncertain effects in menstrual blood loss and adverse effects. A non-randomised comparison in one of the studies points to the value of combining desmopressin and tranexamic acid, which needs to be tested in a formal randomised controlled study comparison.When tranexamic acid was compared to desmopressin, a single study showed a reduction in menstrual blood loss with tranexamic acid use compared to desmopressin.There is a need to evaluate non-surgical methods for treating of menorrhagia in women with bleeding disorders through randomised controlled studies. Such methods would be more acceptable than surgery for women wishing to retain their fertility. Given that women may need to use these treatments throughout their entire reproductive life, long-term side-effects should be evaluated.

Recurrent catamenial pneumothorax suggestive of pleural endometriosis

A 42-year-old multiparous patient presented for consultation as a referral for management of recurrent catamenial pneumothorax. Evaluation by a pulmonologist failed to reveal any chest masses. She was treated for endometriosis using Danazol 800 mg daily for 6 months. Pneumothorax did not recur during treatment and during follow-up visits.

A comparative treatment trial of endometriosis using the gonadotrophin-releasing hormone agonist, nafarelin, and the synthetic steroid, danazol

A randomized and double-blind trial was carried out comparing intranasal nafarelin acetate (400 micrograms daily) and oral danazol (600 mg daily), given over 6 months, in the treatment of 49 patients with laparoscopically proven endometriosis. Both drugs produced a highly significant and similar reduction (of 60 to 70%) in objective American Fertility Society scoring, even in severe disease. No effect was seen on adhesions. Both drugs suppressed oestradiol levels to a similar extent, although nafarelin caused a substantial rise in the first 2 weeks after the initiation of therapy. Nafarelin suppressed LH substantially and FSH, testosterone and prolactin to a small degree, whereas FSH and LH increased slightly during danazol. Pregnancies occurred in 12 of 22 infertile women in the 12 months following nafarelin, and in 6 of 14 in the danazol group. Side-effects were reported at a similar rate with both drugs, but the pattern was different. Hot flushes were the predominant side effect with nafarelin, although oestradiol levels were not suppressed to the extent expected. Small amounts of spotting or light bleeding were experienced with both drugs, but these tended to decrease with time with nafarelin and increase with danazol.

A new therapy for pelvic endometriosis and uterine adenomyosis: local effect of vaginal and intrauterine danazol application

In order to investigate the effect of the local direct action of danazol upon endometriosis, intravaginal and intrauterine application were tried. A vaginal danazol ring containing 2 g to 3.5 g danazol not only reduced both dysmenorrhea and the extent of pelvic endometriosis in all 35 infertile women, but also resulted in conception in 13 out of 35 infertile women while the vaginal ring was in place. Uterine adenomyosis usually fails to respond to oral danazol therapy, but an intrauterine device containing 175 mg of danazol was effective in reducing the size of the uterus and in inducing pregnancy in 66.6% cases. It is noteworthy that this vaginal or intrauterine danazol therapy did not inhibit ovulation, but still effected atrophy of endometriosis and aided in the establishment of pregnancy. These results clearly demonstrate that the main mode of action of danazol is its direct action on endometriotic cells.

Testis functions and sexual potentia in langur monkey treated with a combination steroidal contraceptive formulation

Administration of a combination formulation of danazol (100 mg/day; oral) plus testosterone enanthate (TE) (50 mg/15 days; i.m.) for 30 to 60 days in adult male langur monkeys resulted in the reversible suppression of testicular function without affecting the sexual potentia. Testicular weight and volume decreased significantly along with the mass atrophy of germinal epithelium and impaired morphology of Leydig and Sertoli cells. A conspicuous shrinkage of seminiferous tubules, Leydig cell nuclei and Sertoli cell nuclei was noted. Elevation of testicular cholesterol, total lipids, glycogen and phosphatases activity with the depletion of total proteins, nucleic acid, sialic acid and fructose was noteworthy. All changes were maintained during maintenance dose studies (danazol: 50 mg/day; oral plus TE: 50 mg/15 days; i.m.) for 60 days. Resumption of all measures to normal was evident following 120 days of recovery. It can be concluded that the exogenous TE substitutes the serum testosterone levels to maintain extratesticular androgen actions even after interference by danazol of Leydig cell function along with spermatogenesis inhibition.

A possible mechanism of action of danazol and an ethinylestradiol/norgestrel combination used as postcoital contraceptive agents

Twenty-seven women requesting postcoital contraception were randomly allocated to take an ethinylestradiol/dl-norgestrel combination or danazol. Urine specimens were assayed for luteinising hormone (LH) and pregnanediol-3-glucuronide (P3G) levels from the day of the postcoital treatment to the next period. In addition, the urine samples of these recruits and 12 additional women were assayed for the Beta-subunit of human chorionic gonadotropin (B-hCG). A consistent pattern of alteration in urinary steroids was lacking, indicating a heterogeneous effect on ovarian function. There was no evidence of early pregnancy in successfully treated cases. We suggest that the main mechanism of action of these drugs is at the endometrial level.

Cytoplasmic and nuclear estrogen binding capacity in the rat uterus during treatment with danazol and testosterone

Danazol, testosterone and dihydrotestosterone (DHT) were tested as competitors for estrogen receptors on immature rat uterus cytosol. No competitive binding could be demonstrated for any of these steroids. After that, prepubertal Wistar rats were exposed to danazol, testosterone or propylene glycol (control) for 3 days or 17 days. After the appropriate exposure to medication, the animals were killed. Both danazol and testosterone appeared to be uterotropic after 3 days of treatment, although the increase in the uterine weight was significant only in the danazol-treated group (p less than 0.05). This effect was lost after 17 days of treatment. Estradiol receptor binding assays were done on the cytosolic and nuclear fractions of the homogenized uterine tissue of each group. The estrogen binding capacity of cytosols was increased in both the danazol (p less than 0.05) and the testosterone (p less than 0.01) groups after 3 days of treatment. A parallel increase was found in the nuclear fraction of both groups. After 17 days of treatment, the comparison between the 3 groups showed no differences in the cytosolic or nuclear estrogen binding capacity. The information provided by this study suggests that some effects of danazol may be due to an androgenic action and that may be associated to increases in the free fraction of testosterone.

The biochemistry of human endometrium after two regimens of postcoital contraception: a dl-norgestrel/ethinylestradiol combination or danazol

A combination of 0.5 mg levonorgestrel (in 1 mg dl-norgestrel) and 0.1 mg ethinylestradiol was administered to eight volunteers 48 hours after the start of the luteinizing hormone surge. A second dose was given 12 hours later. Endometrial samples were obtained 24 hours after the first dose was given. The steroid receptor concentration was compared with ovulatory spontaneous cycles. The dl-norgestrel/ethinylestradiol combination caused a significant reduction in receptor concentration. Isocitrate dehydrogenase (a progestin-sensitive enzyme) was also altered, suggesting an effect on endometrial metabolism. Danazol was used in a similar fashion, with two doses each of 400 mg. Nine volunteers were studied. A similar pattern of alteration of endometrial biochemistry was demonstrated but did not reach statistical significance. The relevance to the postcoital use of hormones is discussed.

Treatment of dysfunctional uterine bleeding with danazol

Twenty-six women completed a 6-month course of treatment with danazol (at various dosages between 200 and 800 mg daily) for menorrhagia due to dysfunctional uterine bleeding. Objective measurements of menstrual blood loss (MBL) were undertaken in 9 women, while the remainder merely recorded a detailed prospective but subjective menstrual calendar. A very substantial decrease in blood loss was recorded by all women, and the majority of women on 400-800 mg daily developed amenorrhoea by 3 months. Six women experienced episodes of prolonged or frequent bleeding or spotting throughout the 6 months. Three women used 200 mg daily throughout with a mean measured MBL falling from 95.3 ml to less than 14 ml per month after 2 months therapy. This may become a valuable therapy for menorrhagia for women requiring temporary medical management. However, possibilities for long-term therapy may be limited in some women by side-effects and metabolic effects.

Changes in the biochemical composition of semen following danazol plus testosterone enanthate administration to the langur monkey

Changes in the biochemical composition of semen, which reflect the accessory sex organ functions, following danazol (100 mg/day; orally) plus testosterone enanthate (50 mg/month; i.m.) administration have been investigated in langur monkey. The levels of acid phosphatase, lactic dehydrogenase and glycerylphosphorylcholine in the semen decreased significantly; whereas fructose, citric acid, magnesium and semen volume did not show any significant changes. A gradual decrease in the motility and count of spermatozoa was observed. At 60 days of treatment all animals became azoospermic. No drug related hematological changes were observed. The combination therapy impaired the epididymal and prostatic functions along with suppression of spermatogenesis.

Danazol binding to steroid receptors in human uterine endometrium

To understand the mechanism of action of danazol, the binding of danazol to multiple classes of intracellular steroid binding proteins was studied in the human uterine endometrium. Danazol bound to endometrial receptors for estrogen, progesterone, and androgen and seemed to bind to endometrial intracellular corticosteroid-binding globulin and sex-hormone-binding globulin. Danazol occupies almost all binding sites of steroids in the steroid target cells in spite of the presence of endogenous steroids. It is speculated that the binding behavior of danazol may be related to its therapeutic effect on endometriosis.

Serum hormone and steroid hormone receptor levels during luteal-phase and long-term treatment with danazol

This study was designed to clarify the effects of danazol on levels of serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, progesterone (P), and 17 beta-estradiol and endometrial steroid receptors (for estrogen [ER], progestin [PR], and androgen [AR] ) during luteal-phase and long-term treatment. These levels were compared with midluteal-phase levels for a histologically in-phase endometrium. Danazol given during the luteal phase to patients with in-phase endometrium decreased endometrial steroid receptor levels (total ER and total PR), and decreased serum P, LH, and FSH levels. Ten of the 17 patients treated (59%) still had in-phase endometrium. Danazol (400 mg/day) given for 1 month or more to patients with pelvic endometriosis increased serum LH and FSH levels within the normal range and endometrial total ER and PR levels. It appears that the effects of short-term and long-term treatment with danazol on serum hormone and endometrial steroid receptor levels differ.

The interaction of human endometrial and myometrial steroid receptors with danazol

The affinity of danazol for oestrogen, androgen and progesterone receptors in human endometrium and myometrium was determined, to study the mechanism of action of this drug in the treatment of endometriosis. The ability of danazol to combine with each of the three types of receptor was similar in both endometrium and myometrium. The capacity of danazol to compete with oestradiol-17 beta for the oestrogen receptor was very low (1.72 +/- 0.48 X 10(-3%) cross reaction, mean +/- SEM) and danazol, at the maximum concentration used, was unable to saturate the receptor; but danazol's ability to compete with progesterone for its receptor was considerably higher (8.41 +/- 1.65% using progesterone, 1.95 +/- 0.41% using R5020) and was saturable. Danazol was also able to displace dihydrotestosterone from the cytosol androgen receptor (6.29 +/- 1.82% cross reaction). The association constant of oestradiol for the endometrial and myometrial oestrogen receptors was 2.19 X 10(9)M-1 and 7.45 X 10(9)M-1 respectively, while that of progesterone and dihydrotestosterone for their receptors was similar in endometrium and myometrium (mean 0.25 +/- 0.06 X 10(9) M-1 and 3.62 +/- 1.67 X 10(9) M-1 respectively). Using R5020, the association constant for the myometrial progesterone receptor was 2.50 +/- 0.73 X 10(9) M-1. We conclude that, in view of the high circulating levels of danazol present in patients being treated for endometriosis, it is possible that danazol may bind to, and partly saturate, endometrial and myometrial oestrogen, progesterone and androgen receptors during treatment. An explanation may thus be provided for some of the diverse actions of this drug.

Side effects of danazol compared with an ethinyloestradiol/norgestrel combination when used for postcoital contraception

A postcoital contraceptive with a lower incidence of nausea and vomiting than oestrogen-progestogen combinations would be a significant advance. During a nine-month period, 101 women were treated at the Margaret Pyke Centre in London with either an oestrogen-progestogen combination or with danazol. A comparison of the side effects of each drug is reported. Those treated with danazol were six times less likely to experience nausea and none vomited. With the exception of breast symptoms, other side effects were five times less common in women receiving danazol. These differences give danazol a clear advantage in terms of patient acceptability. Further experience will enable the efficacy of danazol to be evaluated and so determine whether this drug should become the preferred hormonal postcoital treatment.

Changes of prolactin secretion following long-term danazol application

Patients (n = 10) with endometriosis or fibrocystic mammary disease were treated with an oral dose of 4 x 200 mg danazol for 6 months. Prolactin and gonadotropin secretion was evaluated before, and in some of them during 1, 3, and 6 months of therapy, as well as 4 weeks after discontinuation of the steroid. Prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, and progesterone were measured before a bolus of 10 mg metoclopramide and 25 micrograms LH-releasing hormone (LH-RH) had been given. The serum concentrations of prolactin and LH were estimated 25 minutes and those of FSH 45 minutes thereafter. Basal and stimulated serum prolactin levels, measured during the luteal phase of the control cycle preceding danazol application, decreased continuously, reaching serum concentrations seen during the early follicular phase of the cycle. This was paralleled by a decrease of estradiol and a lack of progesterone secretion. While basal and LH-RH-stimulated LH was practically unchanged, basal and stimulated FSH showed a significant increase. Within 4 weeks of discontinuation of the drug all hormonal parameters were similar to pretreatment values. The data presented may explain the beneficial effect of the drug on fibrocystic mammary disease, i.e., by the decrease of serum and pituitary prolactin. The selective increase of FSH secretion is unclear but may reflect the lack of negative feedback mechanisms of follicular inhibin.