Selective modulation of estrogen receptor in obese men with androgen deficiency: A systematic review and meta-analysis.

BACKGROUND: Although selective estrogen receptor modulators have been proposed as a treatment for men with central functional hypogonadism, only a few data have been produced in men with obesity-related functional androgen deficiency. OBJECTIVE: To determine whether and to what extent selective estrogen receptor modulators are an effective and safe therapy in men with obesity-related functional androgen deficiency. MATERIALS AND METHODS: A thorough search of PubMed, Web of Science, Scopus, and Cochrane Library databases was performed to identify studies comparing testosterone levels before and after treatment. Mean differences with 95% coefficient intervals were combined using random effects models. Funnel plot, Egger's test, and trim-and-fill analysis were used to assess publication bias. RESULTS: Seven studies met the inclusion criteria providing information on 292 men with obesity-related functional androgen deficiency treated with clomiphene citrate (12.5-50 mg daily) or enclomiphene citrate (12.5-25 mg daily) for 1.5-4 months. The pooled estimates indicated a significant increase in testosterone levels both with clomiphene (mean difference: 11.56 nmol/L; 95% coefficient interval: 9.68, 13.43; I2  = 69%, pfor heterogeneity  = 0.01) and enclomiphene citrate (mean difference: 7.50 nmol/L; 95% coefficient interval: 6.52, 8.48; I2  = 4%, pfor heterogeneity  = 0.37). After the exclusion of one study on severely obese men, who exhibited the highest response rate to clomiphene citrate, the heterogeneity disappeared (mean difference: 10.27 nmol/L; 95% coefficient interval: 9.39, 11.16; I2  = 0%, pfor heterogeneity  = 0.66). No publication bias was revealed by Egger's test and trim-and-fill analysis. No treatment-related unexpected findings regarding safety profile were registered. DISCUSSION AND CONCLUSION: Treatment with clomiphene citrate and enclomiphene citrate may be an effective and safe alternative to testosterone replacement therapy in men with obesity-related functional androgen deficiency. Further long-term studies are warranted to define clinical reflections of the selective estrogen receptor modulators-induced increase in testosterone levels and to better clarify the safety profile.

Enclomiphene citrate: A treatment that maintains fertility in men with secondary hypogonadism.

INTRODUCTION: Hypogonadism is an important issue among the male population. Treatments such as exogenous testosterone have become very popular. One of the adverse effects of testosterone is its suppression of fertility. This has lead to the use of alternative therapies such as selective estrogen receptor modulators (SERMs) that aim to correct hypogonadism without reducing fertility. Areas covered: The SERM, clomiphene citrate, which is approved by the FDA for the treatment of ovarian dysfunction, has been shown to have beneficial effects on male hypogonadism. Clomiphene citrate exists as a mixture of both the cis-isomer (zuclomiphene) and the trans-isomer (enclomiphene). The literature has suggested that most of the beneficial effects of clomiphene are due to the trans-isomer enclomiphene. Zuclomiphene contributes little to the intended outcomes. The purpose of this drug profile is to examine the available literature on the trans-isomer enclomiphene. Expert opinion: Enclomiphene has been shown to increase testosterone levels while stimulating FSH and LH production. Initial studies demonstrated that enclomiphene maintains the androgenic benefit of clomiphene citrate without the undesirable effects attributable to zuclomiphene. This article reviews the difficulties associated with the FDA approval of a new molecular entity related to the treatment of hypogonadism.

Enclomiphene citrate for the treatment of secondary male hypogonadism.

INTRODUCTION: Hypogonadism is a growing concern in an aging male population. Historically treated using exogenous testosterone, concerns about possible adverse effects of testosterone have led physicians to seek alternative treatment approaches. AREAS COVERED: Enclomiphene citrate is the trans isomer of clomiphene citrate, a non-steroidal estrogen receptor antagonist that is FDA-approved for the treatment of ovarian dysfunction in women. Clomiphene citrate has also been used off-label for many years to treat secondary male hypogonadism, particularly in the setting of male infertility. Here we review the literature examining the efficacy and safety of enclomiphene citrate in the setting of androgen deficiency. EXPERT OPINION: Initial results support the conclusion that enclomiphene citrate increases serum testosterone levels by raising luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, without negatively impacting semen parameters. The ability to treat testosterone deficiency in men while maintaining fertility supports a role for enclomiphene citrate in the treatment of men in whom testosterone therapy is not a suitable option.

Enclomiphene citrate stimulates testosterone production while preventing oligospermia: a randomized phase II clinical trial comparing topical testosterone.

OBJECTIVE: To determine the effect of enclomiphene citrate in men with secondary hypogonadism. DESIGN: Phase II clinical trial. SETTING: Community dwelling men making visits to physician offices. PATIENT(S): Men with secondary hypogonadism. INTERVENTION(S): Oral administration of enclomiphene citrate or 1% topical T gel. MAIN OUTCOME MEASURE(S): Luteinizing hormone, FSH, T, and semen analysis. RESULT(S): Treatment with enclomiphene citrate resulted in increased morning serum T, E2, and LH levels similar to those obtained with a topical T gel in men with secondary hypogonadism. Follicle-stimulating hormone and LH were increased with enclomiphene, and sperm counts were conserved. CONCLUSION(S): Enclomiphene citrate reverses the two hallmarks of secondary hypogonadism, namely, low serum total T and low or inappropriately normal LH while preserving sperm production. CLINICAL TRIAL REGISTRATION NUMBER: NCT01270841 (ClinicalTrials.gov Identifier NCT01270841).