Dutasteride for the Treatment of Androgenetic Alopecia: An Updated Review

BACKGROUND

Androgenetic alopecia (AGA) is a common skin disease characterized by gradually miniaturized hair follicles, which manifests as progressive hair thinning and produces a bald appearance. Currently, finasteride is approved by the Food and Drug Administration (FDA) for the treatment of AGA, but its efficacy remains poor in some patients.

SUMMARY

Compared to finasteride, oral dutasteride has better efficacy and similar tolerability, and most adverse events are mild and reversible, making it an effective option for AGA, but its sexual adverse events and potential psychiatric risks still need to be concerned. Mesotherapy with dutasteride and microneedling combined with dutasteride solution can reduce adverse events caused by oral medication and exhibit certain efficacy, but standardized treatment protocols and large-scale clinical trials are still needed in the future. Liposomes or nanoparticles of dutasteride are under development and may become an efficient topical formulation.

KEY MESSAGES

We have summarized the efficacy and AEs of dutasteride in treating AGA under different administration methods and the promise of novel topical drug carriers.

Development and Evaluation of Dutasteride Nanoemulgel for the Topical Delivery against Androgenic Alopecia

BACKGROUND

Dutasteride is approximately three times more potent than finasteride in treating alopecia. For reducing systemic exposure to dihydrotestosterone (DHT), researchers have shown special interest in developing topical formulations for treating androgenic alopecia. Dutasteride emulsification may lead to good skin penetration and improved availability in different lipophilic skin environments.

OBJECTIVES

This study aimed to encapsulate the drug into the lipidic carrier system for better local availability in the scalp skin, develop and evaluate nanoemulgel of dutasteride to ensure efficient topical administration, and perform the in-vivo activity of the developed gel for improved efficacy against alopecia.

METHODS

Dutasteride-loaded nanoemulsion was prepared by a high-speed homogenizer, followed by thickening of the dispersion using Carbopol 934. Skin permeation and accumulation were investigated in the excised skin of male Swiss albino mice. The nanoemulgel was characterized based on pH, stress stability, viscosity, and hardness.

RESULTS

The optimized dutasteride-loaded nanoemulsion had a size of 252.33 ± 8.59 nm, PDI of 0.205 ± 0.60, and drug content of 98.65 ± 1.78%. Stress stability was performed was well observed in nanoemulsion formulation. Nanoemulgel evaluation results were as follows: pH 5-6 was desirable for topical application, hardness was 43 gm, and spreadability was 79 gm with in vitro release of nanoemulgel at 91.98% and permeation study at 13.67%.

CONCLUSION

The in vivo studies demonstrated the growth of newer hair follicles and increased hair diameter and length in dutasteride-loaded nanoemulgel-treated alopecia animals compared to the marketed sample and testosterone-treated group. Provided with the same and long-term storage stability, the developed formulation is supposed to offer a good option for the topical administration of dutasteride in treating androgenic alopecia.

Electrophotochemical Synthesis Facilitated Trifluoromethylation of Arenes Using Trifluoroacetic Acid

The trifluoromethyl (CF3) group is an essential moiety in medicinal chemistry due to its unique physicochemical properties. While trifluoroacetic acid (TFA) is an inexpensive and easily accessible reagent, its use as a source of CF3 is highly challenging due to its high oxidation potential. In this study, we present a novel electrophotochemical approach that enables the use of TFA as the CF3 source for the selective, catalyst- and oxidant-free trifluoromethylation of (hetero)arenes. Key to our approach is the selective oxidation of TFA over arenes, generating CF3 radicals through oxidative decarboxylation. This strategy enables the sustainable and environmentally-friendly synthesis of CF3-, CF2H- and perfluoroalkyl-containing (hetero)arenes with a broad range of substrates. Importantly, our results demonstrate significantly improved chemoselectivity by light irradiation, opening up new possibilities for the synthetic and medicinal applications of TFA as an ideal yet underutilized CF3 source.

A New Chemometrically Assisted UV Spectrophotometric Method for Simultaneous Determination of Tamsulosin and Dutasteride in Their Pharmaceutical Mixture

BACKGROUND

Tamsulosin (TAM) and dutasteride (DUT) are ranked among the most frequently prescribed therapies in urology. Interestingly, studies have also been carried out on TAM/DUT in terms of their ability to protect against recent COVID-19. However, very few studies were reported for their simultaneous quantification in their combined dosage form and were mainly based on chromatographic analysis. Subsequently, it is very important to offer a simple, selective, sensitive, and rapid method for the quantification of TAM and DUT in their challenging dosage form.

OBJECTIVE

In this study, a new chemometrically assisted ultraviolet (UV) spectrophotometric method has been presented for the quantification of TAM and DUT without any prior separation.

METHOD

For the calibration set, a partial factorial experimental design was used, resulting in 25 mixtures with central levels of 20 and 25 μg/mL for TAM and DUT, respectively. In addition, to assess the predictive ability of the developed approaches, another central composite design of 13 samples was used as a validation set. Post-processing by chemometric analysis of the recorded zero-order UV spectra of these sets has been applied. These chemometric approaches include partial least-squares (PLS) and genetic algorithm (GA), as an effective variable selection technique, coupled with PLS.

RESULTS

The models' validation criteria displayed excellent recoveries and lower errors of prediction.

CONCLUSIONS

The proposed models were effectively used to determine TAM/DUT in their combined dosage form, and statistical comparison with the reported method revealed satisfactory results.

HIGHLIGHTS

Overall, this work presents powerful simple, selective, sensitive, and precise methods for simultaneous quantification of TAM/DUT in their dosage form with satisfactory results. The predictive ability and accuracy of the developed methods offer the opportunity to be employed as a quality control technique for the routine analysis of TAM/DUT when chromatographic instruments are not available.

FDA-Approved Trifluoromethyl Group-Containing Drugs: A Review of 20 Years

As people around the world regard 2020 as the year of COVID-19, the medical community considers this year to be the second-best year, shared with the year 1996, with respect to the number of drug molecules approved by the US Food and Drug Administration (FDA). Both years, 2020 and 1996, had a record of 53 new drug molecules approved by the FDA. In the year 2020, 53 new chemical entities and 13 biological medicines were approved, including 10 monoclonal antibodies, 2 antibody-drug conjugates, 3 peptides, and 2 oligonucleotides. Among them, most of the compounds were found to have fluorine or fluorine-containing functional groups exhibiting numerous pharmacological activities. Herein, we summarized the trifluoromethyl (TFM, -CF3)-group-containing FDA-approved drugs for the last 20 years. This article specially features and details the previous 20-year literature data, covering CF3-incorporated potential drug molecules, including their syntheses and uses for various diseases and disorders. The review covers the detailed chemistry of 19 FDA-approved drugs in the past 20 years, which contains the TFM group as one of the pharmacophores.

Epigenetic regulation of 5α reductase-1 underlies adaptive plasticity of reproductive function and pubertal timing

Background

Women facing increased energetic demands in childhood commonly have altered adult ovarian activity and shorter reproductive lifespan, possibly comprising a strategy to optimize reproductive success. Here, we sought to understand the mechanisms of early-life programming of reproductive function, by integrating analysis of reproductive tissues in an appropriate mouse model with methylation analysis of proxy tissue DNA in a well-characterized population of Bangladeshi migrants in the UK. Bangladeshi women whose childhood was in Bangladesh were found to have later pubertal onset and lower age-matched ovarian reserve than Bangladeshi women who grew-up in England. Subsequently, we aimed to explore the potential relevance to the altered reproductive phenotype of one of the genes that emerged from the screens.

Results

Of the genes associated with differential methylation in the Bangladeshi women whose childhood was in Bangladesh as compared to Bangladeshi women who grew up in the UK, 13 correlated with altered expression of the orthologous gene in the mouse model ovaries. These mice had delayed pubertal onset and a smaller ovarian reserve compared to controls. The most relevant of these genes for reproductive function appeared to be SRD5A1, which encodes the steroidogenic enzyme 5α reductase-1. SRD5A1 was more methylated at the same transcriptional enhancer in mice ovaries as in the women’s buccal DNA, and its expression was lower in the hypothalamus of the mice as well, suggesting a possible role in the central control of reproduction. The expression of Kiss1 and Gnrh was also lower in these mice compared to controls, and inhibition of 5α reductase-1 reduced Kiss1 and Gnrh mRNA levels and blocked GnRH release in GnRH neuronal cell cultures. Crucially, we show that inhibition of this enzyme in female mice in vivo delayed pubertal onset.

Conclusions

SRD5A1/5α reductase-1 responds epigenetically to the environment and its downregulation appears to alter the reproductive phenotype. These findings help to explain diversity in reproductive characteristics and how they are shaped by early-life environment and reveal novel pathways that might be targeted to mitigate health issues caused by life-history trade-offs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-021-01219-6.

LC-MS/MS determination of dutasteride and its major metabolites in human plasma

Dutasteride is a specific and selective inhibitor of both 5α-reductase isoforms used mainly in benign prostatic hyperplasia and lower urinary tract symptoms. Although the drug is extensively metabolized in humans, data on the concentrations of its main metabolites are lacking. There is also a lack of data on dutasteride stability in frozen plasma samples. Our method was used to determine dutasteride and its active metabolites: 4'-hydroxydutasteride, 6β-hydroxydutasteride, and 1,2-dihydrodutasteride in plasma after a single administration of 0.5 mg of dutasteride. We also assessed the long-term stability (two years in the freezer) of dutasteride in clinical samples. The developed method covered the range of 0.1-3.5 ng/mL for dutasteride and 0.08-1.2 ng/mL for 1,2-dihydrodutasteride, 4'-hydroxydutasteride, 6β-hydroxydutasteride. It was proved to be reliable as it met all validation criteria required by the European Medicine Agency for bioanalytical methods. 4'-hydroxydutasteride and 1,2-dihydrodutasteride concentrations in plasma were higher than 6β-hydroxydutasteride. Dutasteride was stable in the freezer for up to 2 years in clinical samples. Thus within 1014 days of storage (below - 65 °C), samples can be reanalyzed without the risk of unreliable results.

Synthesis of 3,5-Bis(trifluoromethyl)phenyl-Substituted Pyrazole Derivatives as Potent Growth Inhibitors of Drug-Resistant Bacteria

Enterococci and methicillin-resistant S. aureus (MRSA) are among the menacing bacterial pathogens. Novel antibiotics are urgently needed to tackle these antibiotic-resistant bacterial infections. This article reports the design, synthesis, and antimicrobial studies of 30 novel pyrazole derivatives. Most of the synthesized compounds are potent growth inhibitors of planktonic Gram-positive bacteria with minimum inhibitory concertation (MIC) values as low as 0.25 µg/mL. Further studies led to the discovery of several lead compounds, which are bactericidal and potent against MRSA persisters. Compounds 11, 28, and 29 are potent against S. aureus biofilms with minimum biofilm eradication concentration (MBEC) values as low as 1 µg/mL.

The role of preoperative dutasteride in reducing bleeding during transurethral resection of the prostate: A systematic review and meta-analysis of randomized controlled trials

Objective

Bleeding is one of the most common complications of transurethral resection of the prostate (TURP). Several previous studies reported that administering dutasteride before surgery could reduce perioperative bleeding. We aimed to evaluate the efficacy of preoperative dutasteride treatment in benign prostatic hyperplasia patients undergoing TURP by performing a meta-analysis of relevant randomized controlled trials (RCTs).

Methods

A comprehensive literature search was performed through the electronic databases including Medline, Cochrane Library, Google Scholar, and ClinicalTrial.gov in October 2020. RCTs evaluating the role of dutasteride for TURP were screened using the eligibility criteria and the quality of RCTs was assessed using the Cochrane Risk of Bias Tool. The heterogeneity was assessed using I² statistic. The measured outcomes were hemoglobin (Hb) levels, perioperative blood loss, blood transfusion, microvessel density (MVD), and operation time. Data were pooled as mean difference (MD) and odds ratio (OR).

Results

A total of 11 RCTs consisting of 627 samples from the treatment group and 615 samples from the placebo group were analyzed. Patients that received dutasteride had less reduction in Hb levels (MD −1.10, 95% confidence interval [CI] −1.39 to −0.81, p<0.00001). Dutasteride also significantly reduced the operation time (MD −1.79, 95% CI −2.97 to −0.61, p=0.003) and transfusion rate after surgery (OR 0.34, 95% CI 0.15 to 0.77, p=0.009) compared to the control group. However, the MVD (MD −3.60, 95% CI −8.04 to 0.84, p=0.11) and perioperative blood loss in dutasteride administration for less than 4 weeks (MD 46.90, 95% CI −144.60 to 238.41, p=0.63) and more than 4 weeks (MD −190.13, 95% CI −378.05 to −2.21, p=0.05) differences were insignificant.

Conclusion

Preoperative administration of dutasteride is able to reduce bleeding during TURP, as indicated by less reduction in Hb level, lower transfusion rate, and less operation time.

Azasteroids from diosgenin: Synthesis and evaluation of their antiproliferative activity

In this work, we report the synthesis of two new azasteroids through the modification of the A and B rings of diosgenin 1. The 4-azasteroid derivative 12 was prepared in three steps using the α,β-insaturated-3-keto compound 11 as a precursor, which was first oxidized with KMnO4/KIO4 followed by an oxidative cleavage of ring A, and subsequently cyclized with an ammonium salt, under focused microwave irradiation for a short time of 3 min. A second azasteroid was synthesized, for which the key step was the Beckmann rearrangement of ring B of the oxime 16, affording the lactam-type enamide 17 in good yield. The methodologies developed for the synthesis of the precursors derivatives 10 and 11 contribute to improved yields, compared to those reported in the literature. The biological activity of the azasteroidal compounds 12 and 17 and their precursors has been evaluated in cervical cancer cells (HeLa), colon (HCT-15), and triple negative breast cancer (MDA-MB-231) lines.

In Vitro and In Vivo Assessment of Metabolic Drug Interaction Potential of Dutasteride with Ketoconazole

Dutasteride (DUT) is a selective, potent, competitive, and irreversible inhibitor of both type-1 and type-2 5α-reductase (5AR) commonly used in the treatment of benign prostatic hyperplasia and androgenetic alopecia. In the present study, we developed a simple and sensitive high-performance liquid chromatography with fluorescence detection (HPLC-FL) method for simultaneous determination of DUT and its major active metabolite, 6β-hydroxydutasteride (H-DUT). Next, the pharmacokinetic interactions of DUT with ketoconazole (KET), a potent CYP3A inhibitor, were comprehensively investigated. In vivo rat intravenous and oral studies revealed that the pharmacokinetics of DUT and H-DUT were significantly altered by the co-administration of KET. Furthermore, the in vitro microsomal metabolism, blood distribution, and protein-binding studies suggest that the altered pharmacokinetics of DUT could be attributed primarily to the inhibition of the DUT metabolism by KET. To the best of our knowledge, this is the first study to show the drug interaction potential of DUT with azole antifungal drugs including KET, together with a newly developed HPLC-FL method for the simultaneous quantification of DUT and H-DUT.

Discovery and development of azasteroids as anticancer agents

Cancer is the second leading cause of death worldwide following cardiovascular diseases. Cancer can be treated by a variety of techniques including surgery, radiation therapy, immunotherapy, and chemotherapy. Choice of the method can be made based on type, physiologic location and the stage of disease progression. Among chemical methods, steroids find broad applications. Azasteroids have N- substitutions in steroidal rings. This structural modification renders azasteroids advantageous in increased effectiveness and reduced side effects. Numerous accounts of cancer efficacy of this family of compounds are available in literature. The progress made in the discovery, synthetic efforts and development of azasteroids as anticancer agents is broadly outlined in this review.

The 11β-hydroxysteroid dehydrogenase isoforms: pivotal catalytic activities yield potent C11-oxy C19 steroids with 11βHSD2 favouring 11-ketotestosterone, 11-ketoandrostenedione and 11-ketoprogesterone biosynthesis

The 11β-hydroxysteroid dehydrogenase (11βHSD) types 1 and 2 are primarily associated with glucocorticoid inactivation and reactivation. Several adrenal C11-oxy C₁₉ and C11-oxy C₂₁ steroids, which have been identified in prostate cancer, 21-hydroxylase deficiency and polycystic ovary syndrome, are substrates for these isozymes. This study describes the kinetic parameters of 11βHSD1 and 11βHSD2 towards the C11-keto and C11-hydroxy derivatives of the C₁₉ and C₂₁ steroids. The apparent K_m and V_max values indicate the more prominent 11βHSD2 activity towards 11β-hydroxy androstenedione, 11β-hydroxytestosterone and 11β-hydroxyprogesterone in contrast to the 11βHSD1 reduction of the C11-keto steroids, as was demonstrated in the LNCaP cell model in the production of 11-ketotestosterone and 11-ketodihydrotestosterone. Data highlighted the role of 11βHSD2 and cytochrome P450 17A1 in the contribution of C11-oxy C₂₁ steroids to the C11-oxy C₁₉ steroid pool in the C11-oxy backdoor pathway. In addition, 11βHSD2 activity, catalysing 11-ketotestosterone biosynthesis, was shown to be key in the production of prostate specific antigen and in the progression of prostate cancer to castration resistant prostate cancer. The study at hand thus provides evidence that 11βHSD isozymes play key roles in pathophysiological states, more so than was previously put forward.

Corni Fructus attenuates testosterone-induced benign prostatic hyperplasia by suppressing 5α-reductase and androgen receptor expression in rats

BACKGROUND/OBJECTIVES

Benign prostatic hypertrophy (BPH) is a major cause of abnormal overgrowth of the prostate mainly in the elderly. Corni Fructus has been reported to be effective in the prevention and treatment of various diseases because of its strong antioxidant effect, but its efficacy against BPH is not yet known. This study was designed to evaluate the therapeutic efficacy of Corni Fructus water extract (CF) in testosterone-induced BPH rats.

MATERIALS/METHODS

To induce BPH, rats were intraperitoneal injected with testosterone propionate (TP). Rats in the treatment group were orally administered with CF with TP injection, and finasteride, which is a selective inhibitor of 5α-reductase type 2, was used as a positive control.

RESULTS

Our results showed that the increased prostate weight and histopathological changes in BPH model rats were suppressed by CF treatment. CF, similar to the finasteride-treated group, decreased the levels of testosterone and dihydrotestosterone by TP treatment in the serum, and it also reduced 5α-reductase expression and concentration in prostate tissue and serum, respectively. In addition, CF significantly blocked the expression of the androgen receptor (AR), AR co-activators, and proliferating cell nuclear antigen in BPH rats, and this blocking was associated with a decrease in prostate-specific antigen levels in serum and prostate tissue.

CONCLUSIONS

These results suggest that CF may weaken the BPH status through the inactivation of at least 5α-reductase and AR activity and may be useful for the clinical treatment of BPH.

Fixed-dose combination therapy with dutasteride and tamsulosin in the management of benign prostatic hyperplasia

Despite their multifactorial etiology, male lower urinary tract symptoms (LUTS) have been traditionally associated with benign prostatic enlargement (BPE) because of benign prostatic hyperplasia (BPH). Several pharmaceutical therapies have been used to manage LUTS, with α1-adrenergic receptor antagonists (α1-blockers) and inhibitors of 5α-reductase (5α-RIs) representing the most commonly prescribed agents currently in use for LUTS treatment. Due to their different modes of action, combined use of α1-blockers and 5α-RIs has been proven to offer more optimal control of symptoms and better associated quality of life, even though higher rates of adverse events have been shown. Following previous studies on the separate administration of dutasteride and tamsulosin, a fixed-dose combination capsule of tamsulosin 0.4 mg and dutasteride 0.5 mg has been approved and released for clinical use in men with BPH. The present review aims to discuss the rationale behind the combined use of tamsulosin and dutasteride for treating male LUTS, and to present the available data on the role of combination therapy in the management of BPH-related symptoms in terms of efficacy and safety. Special attention is given to the impact of combination treatment on the prevention of clinical progression of BPH. Cost-effectiveness of fixed-dose combination and patients' adherence to treatment are also discussed.

Effects of the 5α-reductase inhibitor dutasteride on rat prostate α1A-adrenergic receptor and its mediated contractility

OBJECTIVE

To clarify the possible interference of the 5α-reductase inhibitor dutasteride with α-adrenergic blockers, whose action is mainly mediated by α1A-adrenergic receptor.

METHODS

Male rats were divided into dutasteride and vehicle-treated groups. The drug treatment group was treated with oral dutasteride 0.5 mg/kg/d, and the control group received vehicle only for 2 months. After the 2-month treatment, the rats' ventral prostate weight changes and the testosterone and dihydrotestosterone levels in the serum were measured. In vitro organ-bath studies, real-time polymerase chain reaction, and tissue-segment binding were performed to determine the expression of α1A-adrenergic receptors and its mediated contractility.

RESULTS

Dutasteride treatment significantly decreased the rats' ventral prostate weight, increased their testosterone levels, and decreased the dihydrotestosterone levels in their serum. There were no marked changes in the α1A-adrenergic receptor messenger ribonucleic acid expression, relative phenylephrine-induced contractility, or nerve-mediated contractility between the groups. Dutasteride treatment caused no marked changes in the relative binding capacity of α1A-adrenergic receptor, whereas it greatly decreased the total protein expression of this subtype and its mediated maximal contraction in the whole ventral prostate.

CONCLUSION

These results suggest that dutasteride does not interfere with α-adrenergic blockers but otherwise has beneficial effects on their actions. Therefore, the long-term administration of the combination of dutasteride with an α-adrenergic blocker might be a better choice for the treatment of lower urinary tract symptoms due to benign prostatic hyperplasia.

Natural products in medicine: transformational outcome of synthetic chemistry

This review brings to the forefront key synthetic modifications on natural products (NPs) that have yielded successful drugs. The emphasis is placed on the power of targeted chemical transformations in enhancing the therapeutic value of NPs through optimization of pharmacokinetics, stability, potency, and/or selectivity. Multiple classes of NPs such as macrolides, opioids, steroids, and β-lactams used to treat a variety of conditions such as cancers, infections, inflammation are exemplified. Molecular modeling or X-ray structures of NP/protein complexes supporting the observed boost in therapeutic value of the modified NPs are also discussed. Significant advancement in synthetic chemistry, in structure determination, and in the understanding of factors controlling pharmacokinetics can now better position drug discovery teams to undertake NPs as valuable leads. We hope that the beneficial NPs synthetic modifications outlined here will reignite medicinal chemists' interest in NPs and their derivatives.

Steroidal 5α-reductase and 17α-hydroxylase/17,20-lyase (CYP17) inhibitors useful in the treatment of prostatic diseases

The role of steroidal inhibitors of androgen biosynthesis as potential weapons in the treatment of prostatic diseases, such as benign prostatic hyperplasia and prostatic cancer will be reviewed. Two enzymes have been targeted in the development of inhibitors that potentially could be useful in the management of such conditions. 5α-Reductase is primarily of interest in benign prostatic disease, though some role in the chemoprevention of prostatic carcinoma have been considered, whereas the 17α-hydroxylase/17,20-lyase (CYP17) enzyme is of interest in the treatment of malignant disease. An overview of the main achievements obtained during the past years will be presented, however special focus will be made on steroidal molecules that reached clinical trials or have been commercially launched. Relevant examples of such drugs are finasteride, dutasteride, abiraterone acetate and galeterone (TOK-001, formerly known as VN/124-1). This article is part of a Special Issue entitled "Synthesis and biological testing of steroid derivatives as inhibitors".

Anticancer steroids: linking natural and semi-synthetic compounds

Steroids, a widespread class of natural organic compounds occurring in animals, plants and fungi, have shown great therapeutic value for a broad array of pathologies. The present overview is focused on the anticancer activity of steroids, which is very representative of a rich structural molecular diversity and ability to interact with various biological targets and pathways. This review encompasses the most relevant discoveries on steroid anticancer drugs and leads through the last decade and comprises 668 references.

A dual 5α-reductase inhibitor dutasteride caused reductions in vascular density and area in benign prostatic hyperplasia

Objectives. Dutasteride, a dual 5α-reductase inhibitor, is used to treat benign prostatic hyperplasia. Nevertheless, its histopathological effects on the morphometrics of blood vessels and glands are still controversial. The aim here was to assess the histopathological effects of dutasteride in cases of benign prostatic hyperplasia in a retrospective study. Methods. Patients with benign prostatic hyperplasia more than 40 cm(3) in prostatic volume were administered 0.5 mg of dutasteride daily or left untreated prior to receiving a transurethral resection of the prostate. Images of sections stained with hematoxylin/eosin and with anti-CD31 antibody were analyzed. Results. In the dutasteride-treated group, the duration of administration was 16.3 ± 8.1 weeks. Artery/arteriole density and vein/venule density in benign prostatic tissue were both lower in the dutasteride-treated group than in the control group. The vein/venule area as a percentage of the whole area was also lower in the dutasteride-treated group, while the artery/arteriole area did not show a significant difference. Glandular/CD31-expressing vessel densities as well as glandular/CD31-expressing vessel areas were comparable between the two groups. Conclusions. Dutasteride reduced the artery/arteriole and vein/venule densities and the proportion of vein/venule area in the tissue of patients with benign prostatic hyperplasia.

Establishing the clinical and economic benefits of adherence to 5-alpha reductase inhibitors in benign prostatic hyperplasia: an assessment of Medicare and Medicaid patients

OBJECTIVE

The primary objective of this study was to evaluate the length of 5-alpha reductase inhibitor (5ARI) therapy on the likelihood of acute urinary retention (AUR) and prostate surgery in patients diagnosed with benign prostatic hyperplasia (BPH). Additionally, this study attempted to quantify the relationship between length of 5ARI therapy and monthly BPH-related medical costs.

STUDY DESIGN

This study used MarketScan® claims data from January 1, 2003, to December 31, 2008. Male Medicare patients ≥ 65 years and Medicaid patients ≥ 50 years who received a diagnosis of BPH and at least one claim for a 5ARI during the study period were included. Cox proportional hazards models were used to evaluate the effect of length of therapy on AUR and surgery, whereas generalized linear models were used to assess the effect on costs.

RESULTS

In 28,903 patients, every additional 30 days of 5ARI therapy reduced the likelihood of AUR and prostate surgery by 14 and 11%, respectively, while each 30-day increment of 5ARI therapy reduced BPH-related costs by 15%.

CONCLUSION

For patients remaining on 5ARI therapy, significant clinical and economic benefits may be realized, including reductions in AUR and prostate surgery rates and reduced medical costs for these clinical events.

VAT-1 is a novel pathogenic factor of progressive benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH), arising from prostatic stromal hyperplasia (STH), is a progressive disease associated with bothersome lower urinary tract symptoms (LUTS). The mechanism of this STH remains unclear because there is no suitable model to study BPH pathology. Previously, we reported a new experimental BPH model that is clinically relevant to STH (the STH model). To elucidate prostatic STH mechanism, we used a compound found to be effective in the STH model.

METHODS

A binding protein specific for the effective compound in the STH model was pulled down using a compound-conjugated affinity matrix and identified by mass spectrometry. The RNA interference (RNAi) method was used to confirm the participation of the binding protein in cell proliferation. The binding protein expression in the prostate was assessed by immunohistochemistry.

RESULTS

A benzimidazole derivative (Benz) significantly suppressed growth of implanted urogenital sinuses (UGS; 37.1%) in the STH model and inhibited the proliferation of human prostate stromal cells (PrSC) in a concentration-dependent manner (IC50  = 0.43 µM). Vesicle amine transport protein-1 (VAT-1) was identified as a specific binding protein of Benz. Immunohistochemical analysis showed that the VAT-1 expression level was higher in both epithelial and stromal cells of rat UGS and human BPH tissue than in normal prostate. VAT-1 siRNA markedly inhibited proliferation of PrSC, two androgen-independent prostate cancer cell lines (PC3 and DU145), and suppressed UGS growth (28.2%) in the STH model.

CONCLUSIONS

Here, we demonstrate that VAT-1 is a novel pathogenic factor in BPH associated with cell proliferation.

Acne, dairy and cancer: The 5alpha-P link

A potent link to dairy seems to exist for three hormone-responsive glands. Acne, breast cancer and prostate cancer have all been linked epidemiologically to dairy intake. Although mechanisms postulated here remain to be accurately defined, the likely link involves Insulin-like Growth Factor-1 as a general stimulant, synergized by the steroid hormones present in milk. The IGF-1 may be either absorbed from milk, or stimulated by its ingestion, or both. The 5alpha-reduced compound 5alpha-pregnanedione (5alpha-P) present in milk is a direct precursor of dihydrotestosterone and may act through that pathway in prostate cancer, but 5alpha-P has also recently been shown to be capable of inducing estrogen receptors in breast cancer cells, upregulating cancer cells' sensitivity to estrogen. The introduction of exogenous hormones and growth factors into tissues that have not evolved defensive feedback inhibition of their corresponding endogenous sources is postulated as a direct stimulatory threat to these organ systems, whether for hyperplasia or neoplasia.

Comparison of dutasteride and finasteride for treating benign prostatic hyperplasia: the Enlarged Prostate International Comparator Study (EPICS)

OBJECTIVE

• To assess the efficacy and safety of dutasteride compared with finasteride in treating men with symptomatic benign prostatic hyperplasia (BPH) for 12 months.

PATIENTS AND METHODS

• The Enlarged Prostate International Comparator Study was a multicentre, randomized, double-blind, 12-month, parallel-group study. • Men aged ≥ 50 years with a clinical diagnosis of BPH received once-daily treatment with dutasteride 0.5 mg (n= 813) or finasteride 5 mg (n= 817). After a 4-week placebo run-in period, patients were randomized to receive dutasteride or finasteride for 48 weeks, followed by an optional 24-month, open-label phase, during which patients received dutasteride 0.5 mg once daily. • The primary endpoint was change in prostate volume, and the secondary endpoints included improvement in American Urological Association Symptom Index (AUA-SI) scores, improvement in maximum urinary flow rate (Q(max)) and long-term safety in the 24-month open-label phase.

RESULTS

• Both dutasteride and finasteride were effective at reducing prostate volume with no significant difference between the two treatments during the study. • Similar reductions in mean AUA-SI scores and Q(max) were also observed for men in both treatment groups. • A similar percentage of adverse events was experienced by patients of both treatment groups, and no new adverse events were reported in the open-label phase.

CONCLUSION

• Dutasteride and finasteride, when administered for 12 months, were similarly effective in reducing prostate volume and improving Q(max) and urinary symptoms associated with BPH in men with an enlarged prostate.

Effect of combination treatment on patient-related outcome measures in benign prostatic hyperplasia: clinical utility of dutasteride and tamsulosin

BACKGROUND

Benign prostatic hyperplasia, the fourth most commonly diagnosed medical condition in the elderly, is a major underlying cause of lower urinary tract symptoms in men. Medical therapy is usually the first therapeutic option. Combination therapy is increasingly used for better symptom relief and outcome.

METHODS

We searched the literature using the MEDLINE database for the efficacy of combination therapy in men with benign prostatic hyperplasia in terms of symptom improvement and impact on quality of life.

RESULTS

Combination therapy with dutasteride and tamsulosin not only provides better symptom improvement and improved urinary flow rate, but is also associated with a more favorable impact on quality of life and patient satisfaction with treatment than monotherapy. Combination therapy also reduces the risk of events related to disease progression, such as acute urinary retention and benign prostatic hyperplasia-related surgery.

CONCLUSION

Combination therapy with dutasteride and tamsulosin is highly efficacious as medical therapy for benign prostatic hyperplasia in patients with moderate-to-severe lower urinary tract symptoms.

The effects of injected testosterone dose and age on the conversion of testosterone to estradiol and dihydrotestosterone in young and older men

BACKGROUND

During testosterone (T) therapy, T is partly converted to 17beta-estradiol (E2) and 5alpha-dihydrotestosterone (DHT). Effects of age, testosterone dose, and body composition on total and free E2 and DHT levels are unknown.

OBJECTIVE

We evaluated age and dose-related differences in E2 and DHT levels in response to graded doses of testosterone enanthate in young and older men.

METHODS

Fifty-one young (aged 19-35 yr) and 52 older (aged 59-75 yr) men completed treatment with monthly injections of a GnRH agonist plus randomly assigned weekly doses of testosterone enanthate (25, 50, 125, 300, or 600 mg) for 5 months.

RESULTS

During testosterone administration, total and free E2 levels increased dose-dependently (dose effect, P<0.001) in both young and older men. Total and free E2 levels and E2:T ratios during T administration were higher in older than young men, but age-related differences in free E2 and free E2:T ratios were not significant after adjusting for testosterone levels, percentage fat mass, and SHBG. DHT levels and DHT:T ratios were dose-related but did not differ between young and older men. Mechanistic modeling of free hormone data revealed that the conversions of T to E2 and DHT were both consistent with saturable Michaelis-Menten kinetics. The in vivo Km values were estimated to be 1.83 nm for aromatase and 3.35 nm for 5alpha-reductase, independent of age. The Vmax parameter for E2 was 40% higher in older men than younger men, but Vmax for DHT was not significantly different between age groups.

CONCLUSIONS

During im testosterone administration, E2 and DHT levels exhibit saturable increases with dose. The rate of whole body aromatization is higher in older men, partly related to their higher percentage fat mass, SHBG, and testosterone levels.

Atmospheric pressure photoionization tandem mass spectrometry of androgens in prostate cancer

Androgen deprivation therapy is the most common treatment option for advanced prostate cancer. Almost all prostate cancers recur during androgen deprivation therapy, and new evidence suggests that androgen receptor activation persists despite castrate levels of circulating androgens. Quantitation of tissue levels of androgens is critical to understanding the mechanism of recurrence of prostate cancer during androgen deprivation therapy. A liquid chromatography atmospheric pressure photoionization tandem mass spectrometric method was developed for quantitation of tissue levels of androgens. Quantitation of the saturated keto-steroids dihydrotestosterone and 5-alpha-androstanedione required detection of a novel parent ion, [M + 15](+). The nature of this parent ion was explored, and the method was applied to prostate tissue and cell culture with comparison to results achieved using electrospray ionization.

Secretagogue type, sex-steroid milieu, and abdominal visceral adiposity individually determine secretagogue-stimulated cortisol secretion

DESIGN

While androgens and estrogens control glucocorticoid secretion in animal models, how the sex-steroid milieu determines cortisol secretion in humans is less clear. To address this issue, cortisol was measured in archival sera obtained at 10-min intervals for 5 h in 42 healthy men administered double placebo, placebo and testosterone, testosterone and dutasteride (to block 5alpha-reductases type I and type II), or testosterone and anastrozole (to block aromatase) in a double-blind, placebo-controlled, prospectively randomized design.

METHODS

Subjects received i.v. injection of saline, GHRH, GH-releasing peptide-2 (GHRP-2), somatostatin (SS), and GHRP-2/GHRH/l-arginine (triple stimulus) each on separate mornings fasting. Outcomes comprised cortisol concentrations, pulsatile cortisol secretion, and relationships with age or abdominal visceral fat (AVF).

RESULTS

By ANCOVA, baseline (saline-infused) cortisol concentrations (nmol/l) did not differ among the sex-steroid milieus (overall mean 364+/-14). In contrast, stimulated peak cortisol concentrations were strongly determined by secretagogue type (P<0.001) as follows: triple stimulus (868+/-27)>GHRP-2 (616+/-42)>saline=SS=GHRH (grand mean 420+/-21). After GHRP-2 injection, pulsatile cortisol secretion increased with age (R(2)=0.16, P=0.012). After the triple stimulus, pulsatile cortisol secretion correlated i) inversely with serum 5alpha-dihydrotestosterone (DHT) concentrations (R(2)=0.53, P=0.026) and ii) directly with computerized tomography-estimated AVF (R(2)=0.11, P=0.038).

CONCLUSION

Age, DHT concentrations, AVF, and secretagogue type influence pulsatile cortisol secretion at least in men. Further studies should be performed to assess ACTH secretion and native ghrelin action in defined sex-steroid milieus.

The forefront for novel therapeutic agents based on the pathophysiology of lower urinary tract dysfunction: pathophysiology of voiding dysfunction and pharmacological therapy

Normal lower urinary tract function consists of voiding and storage. During voiding, the pontine micturition reflex center orders the sacral parasympathetic nucleus to increase parasympathetic activity, resulting in urinary bladder detrusor contraction via activation of post-synaptic muscarinic receptors (M2/3) and in the relaxation of both urethral and prostatic smooth muscle by nitric oxide (NO). In addition, the rhabdosphincter relaxes by inhibition of the pudendal nucleus at the sacral portion. During the storage phase, increase in sympathetic activity relaxes the urinary bladder via activation of post-synaptic beta(3)-receptors and in the contraction of both urethral and prostatic smooth muscles via alpha(1)-adrenoceptor. Many factors influence voiding function, including lower urinary tract disorders (benign prostatic hyperplasia in males, urethral stricture) and neurological disorders (central and peripheral). Theories of pharmacotherapy for voiding dysfunction are 1) increase detrusor contractility and 2) decrease urethral resistance. The former includes agonists for muscarinic receptors and cholinesterase inhibitor; and the latter includes alpha(1)-adrenoceptor antagonists, NO donors, benzodiazepines, baclofen, dantrolene, and boturinum toxin.

Current status of 5alpha-reductase inhibitors in the management of lower urinary tract symptoms and BPH

PURPOSE

Benign prostatic hyperplasia (BPH) is a progressive disease that is commonly associated with bothersome lower urinary tract symptoms (LUTS) and might result in complications, such as acute urinary retention and BPH-related surgery. Therefore, the goals of therapy for BPH are not only to improve LUTS in terms of symptoms and urinary flow, but also to identify those patients at a risk of unfavorable disease progression and to optimize their management. This article reviews the current status of therapy with 5alpha-reductase inhibitors (5ARIs), namely fiasteride and dutasteride, for men with LUTS and BPH.

METHOD

Data from key randomized controlled trials (Oxford level 1b) on the use of 5ARIs are analyzed.

RESULTS

The efficacy of 5ARIs either as monotherapy or in combination with alpha(1)-adrenoceptor antagonists in the management of LUTS and the impact of monotherapy and combined therapy on BPH progression are discussed. Further promises, including the withdrawal of the alpha-blocker from the combined medical treatment and the potential clinical implications from the use of 5ARIs for prostate cancer chemoprevention in patients receiving 5ARIs for symptomatic BPH are highlighted.

CONCLUSIONS

Current evidence shows that 5ARIs are effective in treating LUTS and preventing disease progression and represent a recommended option in treatment guidelines for men who have moderate to severe LUTS and enlarged prostates.

Aromatase and 5alpha-reductase inhibition during an exogenous testosterone clamp unveils selective sex steroid modulation of somatostatin and growth hormone secretagogue actions in healthy older men

BACKGROUND

How endogenous testosterone (Te), 5alpha-dihydrotestosterone (DHT), and estradiol (E(2)) regulate pulsatile GH secretion is not understood.

HYPOTHESIS

Conversion of Te to androgenic (Te-->DHT) or estrogenic (Te-->E(2)) products directs GH secretion. SUBJECTS AND LOCATION: Healthy older men (N = 42, ages 50-79 yr) participated at an academic medical center.

METHODS

We inhibited 5alpha-reduction with dutasteride and aromatization with anastrozole during a pharmacological Te clamp and infused somatostatin (SS), GHRH, GH-releasing peptide-2 (GHRP-2), and L-arginine/GHRH/GHRP-2 (triple stimulus) to modulate GH secretion.

ENDPOINTS

Deconvolution-estimated basal and pulsatile GH secretion was assessed.

RESULTS

Administration of Te/placebo elevated Te by 2.8-fold, DHT by 2.6-fold, and E(2) concentrations by 1.9-fold above placebo/placebo. Te/dutasteride and Te/anastrozole reduced stimulated DHT and E(2) by 89 and 86%, respectively. Stepwise forward-selection regression analysis revealed that 1) Te positively determines mean (P = 0.017) and peak (P < 0.001) GH concentrations, basal GH secretion (P = 0.015), and pulsatile GH secretion stimulated by GHRP-2 (P < 0.001); 2) Te and E(2) jointly predict GH responses to the triple stimulus (positively for Te, P = 0.006, and negatively for E(2), P = 0.031); and 3) DHT correlates positively with pulsatile GH secretion during SS infusion (P = 0.011). These effects persisted when abdominal visceral fat was included in the regression.

CONCLUSION

The present outcomes suggest a tetrapartite model of GH regulation in men, in which systemic concentrations of Te, DHT, and E(2) along with abdominal visceral fat determine the selective actions of GH secretagogues and SS.