Effect of tibolone on glucose and lipid metabolism in postmenopausal women

The effect of tibolone treatment on fasting blood sugar, insulin, insulin resistance and endothelial function in postmenopausal women: A meta-analysis of randomized controlled trials

BACKGROUND AND AIM

The menopause is associated in females with the presence of dysglycemia, insulin resistance and with the development of endothelial dysfunction. Tibolone (TIB) is a synthetic steroid compound with selective oestrogenic and, to a lesser extent, progestogenic and androgenic properties prescribed to postmenopausal women to alleviate the symptoms of the climaterium and to prevent the development of osteoporosis. However, the impact of TIB on fasting blood sugar (FBS), insulin, Homeostatic Model Assessment-Insulin Resistance (HOMA-IR) index and flow-mediated dilation (FMD) in women has not been evaluated so far. Thus, to investigate this research question, we conducted the present systematic review and meta-analysis.

METHODS

Two independent reviewers searched the Scopus, Web of Science, PubMed/Medline and Embase databases up to 20 December 2020. The weighted mean differences (WMDs) and the 95% confidence intervals (CI) were calculated using the DerSimonian and Laird random effects models between the TIB and control groups and included in the forest plot.

RESULTS

The overall findings were generated from 12 eligible randomized controlled trials. As compared to controls, TIB administration resulted in a significant reduction of FBS (WMD: -3.06 mg/dL, 95% CI: -5.30 to -0.82, P = 0.007), and of the HOMA-IR index (WMD: -0.61, 95% CI: -1.11 to -0.11, P = 0.01). However, treatment with TIB did not lead to significant changes of the FMD (WMD: 0.78%, 95% CI: -0.20 to 1.77, P = 0.12) or of insulin levels (WMD: -0.10 mIU/L, 95% CI: -2.04 to 1.83, P = 0.91).

CONCLUSION

TIB administration can decrease FBS and the HOMA-IR index in postmenopausal women. However, the use of TIB does not influence insulin levels or FMD.

Microbial biotransformation of bioactive and clinically useful steroids and some salient features of steroids and biotransformation

Steroids are perhaps one of the most widely used group of drugs in present day. Beside the established utilization as immunosuppressive, anti-inflammatory, anti-rheumatic, progestational, diuretic, sedative, anabolic and contraceptive agents, recent applications of steroid compounds include the treatment of some forms of cancer, osteoporosis, HIV infections and treatment of declared AIDS. Steroids isolated are often available in minute amounts. So biotransformation of natural products provides a powerful means in solving supply problems in clinical trials and marketing of the drug for obtaining natural products in bulk amounts. If the structure is complex, it is often an impossible task to isolate enough of the natural products for clinical trials. The microbial biotransformation of steroids yielded several novel metabolites, exhibiting different activities. The metabolites produced from pregnenolone acetate by Cunning hamella elegans and Rhizopus stolonifer were screened against tyrosinase and cholinesterase showed significant inhibitory activities than the parent compound. Diosgenin and its transformed sarsasapogenin were screened for their acetyl cholinesterase and butyryl cholinesterase inhibitory activities. Sarsasapogenin was screened for phytotoxicity, and was found to be more active than the parent compound. Diosgenin, prednisone and their derivatives were screened for their anti-leishmanial activity. All derivatives were found to be more active than the parent compound. The biotransformation of steroids have been reviewed to a little extent. This review focuses on the biotransformation and functions of selected steroids, the classification, advantages and agents of enzymatic biotransformation and examines the potential role of new enzymatically transformed steroids and their derivatives in the chemoprevention and treatment of other diseases. tyrosinase and cholinesterase inhibitory activities, severe asthma, rheumatic disorders, renal disorders and diseases of inflammatory bowel, skin, gastrointestinal tract.

Neuroactive steroids, neurosteroidogenesis and sex

The nervous system is a target and a source of steroids. Neuroactive steroids are steroids that target neurons and glial cells. They include hormonal steroids originated in the peripheral glands, steroids locally synthesized by the neurons and glial cells (neurosteroids) and synthetic steroids, some of them used in clinical practice. Here we review the mechanisms of synthesis, metabolism and action of neuroactive steroids, including the role of epigenetic modifications and the mitochondria in their sex specific actions. We examine sex differences in neuroactive steroid levels under physiological conditions and their role in the establishment of sex dimorphic structures in the nervous system and sex differences in its function. In addition, particular attention is paid to neuroactive steroids under pathological conditions, analyzing how pathology alters their levels and their role as neuroprotective factors, considering the influence of sex in both cases.

Effects of menopause and tibolone on different cardiovascular biomarkers in healthy women

BACKGROUND AND AIM

The effects of tibolone on cardiovascular risk is not yet fully understood today. We designed this study to assess the effect of the menopausal status and tibolone treatment (2.5 mg/day for 3 months) on different biomarkers of cardiovascular risk in healthy women.

METHODS

Blood arterial pressure were measured, and blood samples collected for glucose, lipid profile (total cholesterol, high density lipoproteins, HDL, low density lipoproteins, and triglycerides), inflammatory (C-reactive protein, Interleukin-6, IL-6, tumor necrosis factor alpha, TNF alpha) and oxidative stress (hydroperoxides and antioxidant capacity) evaluation in 15 premenopausal (mean age: 30 +/- 4 years) and 15 postmenopausal (mean age: 52 +/- 3, mean time from menopause 1.4 +/- 0.4 years) women before and after tibolone treatment.

RESULTS

The menopausal status is associated with increased systolic and diastolic pressure (p<0.05), higher IL-6 (p<0.05) and TNF alpha (p<0.01), and lower antioxidants (p<0.01). However, blood pressure (p<0.05), glucose (p<0.05), TNF alpha (p<0.05) and HDL (p<0.05) fell after tibolone, which did not significantly affect levels of the other biochemical parameters.

CONCLUSIONS

As menopause is associated with increased blood pressure, inflammation and oxidative stress, tibolone restores blood pressure and has beneficial effect on inflammation and glycemia without worsening oxidative stress, although it also reduces HDL levels. Such modifications should be taken into account when tailoring menopausal therapies to specific requirements of each woman.

Glucose tolerance of premenopausal women after menopause due to surgical removal of ovaries

OBJECTIVE

To evaluate the influence of the abrupt withdrawal of ovarian function on glucose tolerance by studying premenopausal women before and after oophorectomy.

METHODS

Thirty premenopausal women who needed hysterectomy for benign reasons volunteered for the study in our hospital in Istanbul, Turkey. An oral glucose tolerance test (OGTT) was performed before surgery and 3, 6 and 12 months after surgery. Fasting glucose, fasting insulin levels and insulin/glucose indexes, HOMA indexes, insulin and glucose levels were measured during OGTT.

RESULTS

The mean fasting and 2-h glucose levels of the women did not change significantly during the 12 months of follow-up. However, the glucose levels during the glucose tolerance tests changed significantly after surgery (p<0.05). Insulin responses to the glucose tolerance test also increased significantly (p<0.005). Insulin/glucose indexes were significantly higher after surgery (p<0.005). Type 2 diabetes mellitus was detected in five women and impaired glucose tolerance was detected in 12 of the 30 patients after surgery in the 12-month period.

CONCLUSION

The impairment of carbohydrate metabolism due to an abrupt decrease in natural estrogen levels should be considered before removing the ovaries during hysterectomy in premenopausal patients.

Effect of different preparations of hormone therapy on lipid and glucose metabolism, coagulation factors, and bone mineral density in overweight and obese postmenopausal women

OBJECTIVE

To determine the effects of different preparations of hormone therapy (HT) on lipid and glucose metabolism, coagulation factors, and bone mineral density (BMD) in overweight and obese postmenopausal women.

DESIGN

A randomized, nonblinded, controlled study.

SETTING

Karadeniz Technical University, Department of Obstetrics and Gynecology.

PATIENT(S)

A total of 352 overweight and obese (body mass index >25 kg/m2) postmenopausal women.

INTERVENTION(S)

Ninety women received 2.5 mg of tibolone; 84 received 2 mg of E2 plus 1 mg of norethisterone acetate (E2/NETA); 90 received 0.625 mg of conjugated equine estrogen plus 2.5 mg of medroxyprogesterone acetate (CEE/MPA); and 88 did not receive any menopausal therapy (control).

MAIN OUTCOME MEASURE(S)

At baseline and after 6 months of treatment, we measured total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), insulin, glucose, factor VII, factor VIII, von Willebrand factor, antithrombin III, protein S, protein C, fibrinogen, and BMD at the lumbar spine L1-L4.

RESULT(S)

There were no statistically significant differences among the groups for any variables at baseline. After 6 months of treatment, the three regimens decreased total cholesterol, triglyceride, LDL, and fibrinogen; E2/NETA and CEE/MPA increased HDL, and tibolone decreased HDL; higher insulin concentrations were found in the control and tibolone groups. Body mass index, HDL, fibrinogen levels, and L1-L4 BMD were independent factors in the prediction of HT use.

CONCLUSION(S)

Body mass index, HDL, fibrinogen levels and L1-L4 BMD were independent factors in the prediction of HT use. Treatment with tibolone, E2/NETA, and CEE/MPA resulted in minimal improvement in lumbar spine BMD but had a beneficial effect on the procoagulation system, with minimal changes in glucose metabolism after 6 months of therapy.

Leuprolide acetate treatment with and without coadministration of tibolone in premenopausal women with menstrual cycle–related irritable bowel syndrome

OBJECTIVE

To evaluate the effectiveness of gonadotropin-releasing hormone agonists (GnRH-a) with or without coadministration of tibolone in women with menstrual cycle-related irritable bowel syndrome (IBS).

DESIGN

Prospective, randomized, placebo-controlled clinical trial.

SETTING

Universities of Catanzaro and Naples.

PATIENT(S)

One hundred twenty young premenopausal women with menstrual cycle-related IBS (Rome II criteria).

INTERVENTION(S)

Administration of leuprolide acetate depot (LAD, 11.25 mg IM/3 months) plus tibolone (group A), LAD plus placebo tablets (group B), and injection of a placebo solution plus placebo tablets (group C).

MAIN OUTCOME MEASURE(S)

Severity of bowel symptoms or signs of IBS and quality of life (QoL), at baseline and after 6 months of treatment.

RESULT(S)

In all groups, the mean scores for each symptom or sign of IBS and for QoL were significantly improved after treatment. A significant difference was observed between group C and groups A and B. No difference between these last groups was detected in symptoms or signs of IBS. The QoL scores were significantly higher in group A than in group B.

CONCLUSION(S)

Gondotropin-releasing hormone agonist administration is effective in women with menstrual cycle-related IBS. The addition of tibolone does not reduce effectiveness compared with agonist alone and increases QoL.

Effects of tibolone and conjugated equine estrogens with or without medroxyprogesterone acetate on body composition and fasting carbohydrate measures in surgically postmenopausal monkeys

The effects of tibolone on body weight, body composition, and fasting carbohydrate measures in surgically postmenopausal cynomolgus monkeys were compared to those of conjugated equine estrogens (CEE) with and without medroxyprogesterone acetate (MPA). Monkeys were fed a moderately atherogenic diet with either no hormones (control n = 29), CEE (0.042 mg/kg, n = 27), CEE + MPA (0.167 mg/kg, n = 29), low-dose tibolone (LoTib, 0.05 mg/kg, n = 30), or high-dose tibolone (HiTib, 0.20 mg/kg, n = 31) daily for 2 years. Body weight (BW) was measured throughout the study, and dual-energy x-ray absorptiometry (DEXA) scans of the abdominal region (lumbar vertebrae 1 through 5) were performed at the end of the trial to assess abdominal body composition. Fasting carbohydrate measures (glucose, insulin, C-peptide, and fructosamine) were determined at baseline and after 2 years of treatment. Compared to controls, BW significantly increased and abdominal soft tissue mass was greater (analysis of variance [ANOVA], P <.001, P = 0.003, respectively) in all but the CEE-treated group (P =.78, P =.94, respectively). HiTib-treated monkeys had greater abdominal lean mass compared to controls (P =.008), while there was no significant treatment effect on abdominal fat mass (analysis of covariance [ANCOVA], P =.29). Fasting insulin concentrations and fasting insulin/glucose ratios were greater in CEE + MPA- (P =.002, P =.03, respectively) and HiTib-treated monkeys (P =.03, P =.02, respectively) compared to controls. There was a strong trend for a treatment effect on fasting blood glucose concentration (ANCOVA, P =.06) with CEE + MPA-treated animals having the greatest values, despite no difference in fructosamine concentration (ANCOVA, P =.57). Using these fasting measures, the homeostasis model assessment (HOMA-IR) revealed significant insulin resistance with CEE + MPA treatment compared to controls (P =.008), while the quantitative insulin sensitivity check index (QUICKI) showed significantly impaired insulin sensitivity in all hormone replacement therapy (HRT) groups (all P values <.03), except CEE (P =.12). In conclusion, HRT with CEE + MPA or tibolone results in greater BW, abdominal soft tissue, and insulin resistance (CEE + MPA and HiTib) compared to control-treated monkeys.

Effects of postmenopausal hormone replacement therapy on lipid, lipoprotein, and apolipoprotein (a) concentrations: analysis of studies published from 1974-2000

OBJECTIVE

To establish reference estimates of the effects of different hormone replacement therapy (HRT) regimens on lipid and lipoprotein levels.

DESIGN

Review and pooled analysis of prospective studies published up until the year 2000.

SETTING

Clinical trials centers, hospitals, menopause clinics.

PATIENT(S)

Healthy postmenopausal women.

INTERVENTION(S)

Estrogen alone, estrogen plus progestogen, tibolone, or raloxifene in the treatment of menopausal symptoms.

MAIN OUTCOME MEASURE(S)

Serum high- and low-density lipoprotein (HDL and LDL) cholesterol, total cholesterol, triglycerides, and lipoprotein (a).

RESULT(S)

Two-hundred forty-eight studies provided information on the effects of 42 different HRT regimens. All estrogen alone regimens raised HDL cholesterol and lowered LDL and total cholesterol. Oral estrogens raised triglycerides. Transdermal estradiol 17-beta lowered triglycerides. Progestogens had little effect on estrogen-induced reductions in LDL and total cholesterol. Estrogen-induced increases in HDL and triglycerides were opposed according to type of progestogen, in the order from least to greatest effect: dydrogesterone and medrogestone, progesterone, cyproterone acetate, medroxyprogesterone acetate, transdermal norethindrone acetate, norgestrel, and oral norethindrone acetate. Tibolone decreased HDL cholesterol and triglyceride levels. Raloxifene reduced LDL cholesterol levels. In 41 studies of 20 different formulations, HRT generally lowered lipoprotein (a).

CONCLUSION(S)

Route of estrogen administration and type of progestogen determined differential effects of HRT on lipid and lipoprotein levels. Future work will focus on the interpretation of the clinical significance of these changes.

Differential effects on the androgen status of postmenopausal women treated with tibolone and continuous combined estradiol and norethindrone acetate replacement therapy

OBJECTIVE

To determine serum parameters reflective of androgen status in postmenopausal women using two types of hormone replacement therapy (HRT).

DESIGN

Randomized, double-blind, prospective 1-year trial of two oral HRT regimens.

SETTING

University hospital, department of obstetrics and gynecology, menopause clinic.

PATIENT(S)

100 postmenopausal women > or = 45 years.

INTERVENTION(S)

Daily use of the progestogen tibolone (2.5 mg; n = 50) or continuous combined 17-beta-estradiol (2 mg) and norethindrone acetate (E+NA, 1 mg; n = 50).

MAIN OUTCOME MEASURE(S)

Measurements of total testosterone (total T), dehydroepiandrosterone sulfate (DHEAS), androstenedione (A), FSH, and sex-hormone-binding globulin (SHBG), and calculations of free testosterone (free T). Assessment of changes from baseline within and between groups after 6 and 12 months.

RESULT(S)

We found significant differences (% changes) in the tibolone group compared to baseline within the groups after both 6 and 12 months, respectively. Levels of free T doubled, total T decreased slightly, and SHBG decreased by half; DHEAS increased by approximately 20%; and FSH decreased. In the E+NA group, levels of free T, total T, androstenedione, and FSH all decreased, and SHBG increased. Pre-trial levels of DHEAS, A, and total T were significantly higher in the E+NA group. Between groups throughout the study, the changes from baseline were significant due to the different extent of FSH reduction, and opposite changes of free T, SHBG, and DHEAS.

CONCLUSION(S)

Both regimens modify plasma androgens, DHEAS, and SHBG differently. Tibolone decreased the levels of SHBG, and substantially increased free T and to a lesser extent increased DHEAS; this may reflect a modification of adrenal androgen production. Continuous combined estradiol and norethindrone acetate HRT suppressed the peripheral plasma androgens mediated by increased levels of SHBG.

Use of leuprolide acetate plus tibolone in the treatment of severe premenstrual syndrome

OBJECTIVE

To evaluate the effectiveness of GnRH agonist (GnRH-a) plus tibolone in the treatment of severe premenstrual syndrome (PMS).

DESIGN

Prospective, double-blind, placebo-controlled clinical trial.

SETTING

Department of Obstetrics and Gynecology, University of Naples Federico II, Naples, Italy. PATIENT(S); Thirty patients affected by severe PMS, aged 23-29 years (mean age +/- SD, 25.3 +/- 2.9 years).

INTERVENTION(S)

Treatment for two cycles with leuprolide acetate depot (3.75 mg IM for 28 days) in association with tibolone (2.5 mg/d orally) or placebo (1 tablet per day orally).

MAIN OUTCOME MEASURE(S)

The mean severity of each symptom and sign of PMS was evaluated using a visual analog scale during the last 7 days of each treatment cycle in comparison with the last 7 days of the cycle before treatment.

RESULT(S)

Mean scores for each of the adverse psychological/physical and positive psychological symptoms were significantly improved during treatment. No statistically significant difference was detected between patients treated with tibolone and placebo. A significantly lower number of hot flushes per day was observed in groups treated with GnRH-a and tibolone in comparison with GnRH-a and placebo.

CONCLUSION(S)

Tibolone administered in association with GnRH-a does not reduce the therapeutic effect of GnRH-a in women affected by PMS. Tibolone used in association with GnRH-a may provide long-term medical treatment for women with PMS.

Effects of oestrogen replacement therapy on pattern reversal visual evoked potentials

As a result of a regression in the ovarian functions, oestrogen level in circulation during the menopause drops to 1/50 of its value in the normal reproductive cycle. Excitatory oestrogen increases the sensitivity of the central nervous system to catecholamines by changing the opening frequency of voltage-related L-type calcium channels and augmenting the effect of glutamate; in addition it inhibits the formation of gamma-amino butyric acid (GABA) by the inhibition of glutamate decarboxylase enzyme. It is argued that oestrogen increases transmission in the optic pathways and that oestrogen is responsible for the shorter latency values and higher amplitudes of visual evoked potentials in women. We recorded the monocular pattern reversal visual evoked potentials (PRVEP) of both eyes of 54 post-menopausal women before treatment and of 30 of them after replacement therapy with Tibolon, and of 24 women receiving placebo treatment. The explicit values of P100 latency of right and left eyes before treatment were 98.8 +/- 3.5 and 99.0 +/- 3.3 ms, respectively. The explicit values of P100 latency of right and left eyes after placebo treatment were 98.6 +/- 3.7 and 98.8 +/- 4.0, respectively. The explicit values of P100 latency of right and left eyes after replacement treatment were 94.6 +/- 3.7 and 94.8 +/- 4.0, respectively. We found a statistically significant decrease in the mean PRVEP latencies and a statistically significant increase in mean amplitudes after replacement treatment (P < 0.001) compared with those before treatment and those after placebo treatment. We attributed the changes in PRVEP values after replacement treatment to the action of Tibolon, which acted as a natural sex steroid and speeded the visual transmission time via the widespread receptors in the central nervous system. It is concluded that PRVEP is an objective electrophysiological assessment method in evaluating the efficiency of hormone replacement therapy in post-menopausal women.

Long-term administration of tibolone plus gonadotropin-releasing hormone agonist for the treatment of uterine leiomyomas: effectiveness and effects on vasomotor symptoms, bone mass, and lipid profiles

OBJECTIVE

To evaluate the effects of long-term administration of GnRH agonist (GnRH-a) plus tibolone for uterine leiomyomatosis.

DESIGN

Prospective open clinical trial.

SETTING

Department of Gynecology, Obstetrics and Pathophysiology of Human Reproduction, University of Naples "Federico II", Naples, Italy.

PATIENT(S)

Twenty-five subjects with symptomatic uterine leiomyomas.

INTERVENTION(S)

Treatment for 2 years with leuprolide acetate (3.75 mg IM every 28 days) and tibolone (2.5 mg/d per os).

MAIN OUTCOME MEASURE(S)

Uterine and uterine leiomyoma sizes, endometrial thickness, lumbar spine bone mineral density (BMD), bone metabolism, lipid profile, myoma-related symptoms at baseline and every 6 months. Hot flashes and vaginal bleeding episodes recorded in a daily symptom diary.

RESULT(S)

After 6 months of treatment, a significant reduction was observed in uterine and leiomyoma volumes and myoma-related symptoms compared with baseline values. No significant change was observed in bone turnover, lumbar BMD, or serum total cholesterol, low-density lipoprotein cholesterol, or triglyceride levels. High-density lipoprotein cholesterol values were significantly lower than baseline values after 6 months of treatment but not after 18 months of therapy. A low mean number of hot flashes per day was observed.

CONCLUSION(S)

Long-term administration of GnRH-a plus tibolone reduces hot flashes and prevents bone loss without changing the lipid profile.

Tibolone: a review

Tibolone appears to be at least as efficacious as other forms of hormonal replacement therapy (HRT) on climacteric symptoms. It does not cause withdrawal bleeding when used in women with at least 1 year of amenorrhea. It is, therefore, not indicated in perimenopause because it may cause irregular bleeding. The androgenic action of tibolone may have a two-fold benefit: on the one hand, it may help depression and libido more than other forms of HRT, while, on the other hand, it may improve some lipid parameters such as Lp(a), and triglycerides. However, this androgenic action, may also be responsible for the reduction of HDL cholesterol, that may thus reduce the beneficial effect of tibolone on lipids. It is estimated that only 30% of cardiovascular risk protection of HRT is due to improvement of classical lipids parameters while a great role is played by the direct effect of estrogen on vessels. Tibolone, as well as estrogen, has been shown to induce peripheral vasodilatation and also has a direct effect on vascular reactivity thus increasing peripheral blood flow with no changes in blood pressure or cardiac output. Tibolone seems to exert a similar effect as other forms of HRT on markers of bone metabolism and bone mass, but no data is yet available on fracture prevention.

A clinical trial of the effects of tibolone administered with gonadotropin-releasing hormone analogues for the treatment of uterine leiomyomata

OBJECTIVE

To evaluate the effects of tibolone therapy in association with GnRH-a on uterine leiomyomata, on climacteric-like symptoms, on bone metabolism, and on the lipid profile.

DESIGN

A prospective, randomized, double-blind, placebo-controlled, clinical trial.

SETTING

Department of Gynecology and Obstetrics, University of Naples "Federico II," Naples, Italy.

PATIENT(S)

Fifty women with symptomatic uterine leiomyomata.

INTERVENTION(S)

Six months of treatment with leuprolide acetate (3.75 mg every 28 days IM) combined with daily placebo tablets (group A) or with 2.5-mg of tibolone per os (group B).

MAIN OUTCOME MEASURE(S)

Uterine and uterine leiomyomata sizes, lumbar spine bone mineral density, biochemical markers of bone metabolism, lipid profile, and myoma-related symptoms were measured at baseline and after 6 months of treatment. Daily symptom diary in which hot flushes and vaginal bleeding episodes were recorded.

RESULT(S)

No differences between the 2 groups in uterine and uterine leiomyomata size and myoma-related symptoms were detected. After 6 months of treatment, there were statistically significant changes from baseline in bone mineral density and in biochemical markers of bone metabolism in group A but not in group B. Vasomotor symptoms were significantly lower in group B than in group A. There was a statistically significant increase (P<.01) in serum total cholesterol, high-density lipoprotein cholesterol, and triglycerides in group A after 6 months of treatment in comparison with baseline values. The difference in serum total cholesterol and triglyceride levels after 6 months of treatment in group B was not statistically significant in comparison with baseline values, but was statistically significant in comparison with group A values (P<.01). In group B, levels of high-density lipoprotein cholesterol were significantly lower after 6 months of therapy in comparison with baseline values and in comparison with group A values (P<.01). There were no statistically significant changes at baseline and after 6 months of treatment in the level of low-density lipoprotein cholesterol in either group.

CONCLUSION(S)

Administration of tibolone in association with GnRH-a reduces vasomotor symptoms and prevents bone loss, without compromising the therapeutic efficacy of GnRH-a alone.

The effects of tibolone

Tibolone is a non-bleeding form of hormone replacement therapy (HRT). When ingested, it is broken down into metabolites, of which the progestogenic metabolite predominates at the level of the endometrium, so that an atrophic endometrium is produced. For the postmenopausal woman, the availability of non-bleeding HRT has great appeal, and compliance is substantially improved. Other clinical situations in which tibolone is particularly useful include: women who have had hormone-dependent tumors in the past, women who have had endometriosis and women taking gonadotropin-releasing hormone agonists.