Finasteride and dutasteride are 5-alpha reductase selective inhibitors (5ARIs). They were introduced as therapeutic agents for the treatment of benign prostatic hyperplasia in 1992 and 2002, respectively; finasteride has also been approved for the treatment of androgenetic alopecia since early 2000. These agents inhibit the conversion of testosterone (T) to 5α-dihydrotestosterone (5α-DHT), limiting steroidogenesis and playing a crucial role in the physiological function of the neuroendocrine system. Therefore, it has been proposed that blocking androgen synthesis with the use of 5ARIs would be beneficial in the treatment of various diseases related to states of hyperandrogenism. This review describes the dermatological pathologies in which 5ARIs have been used as part of the treatment, evaluation of the efficacy, and knowledge of the safety profile. Specifically, we discuss the application of 5ARIs in androgenetic alopecia, acne, frontal fibrosing alopecia, hirsutism, and the implications of adverse events associated with its use to inform about the applications of 5ARIs in general dermatology practice.

Prostate cancer is one of the most complex and enigmatic oncologic problems in medicine. It is highly prevalent, particularly in elderly males. Unfortunately, its generally protracted and variable clinical course and high association with treatment-related morbidity raise serious questions about the ideal treatment strategy for the individual patient. 5 alpha-reductase (5AR) inhibitors have a dramatic effect on benign prostatic disease with low toxicity. Thus, there is much interest in the potential role of 5AR inhibitors in the prevention and treatment of prostate cancer. Finasteride is the only agent that has been shown in a randomized clinical trial to decrease the risk of prostate cancer with a reduction of almost 25%. Additionally, a recent analysis of the Prostate Cancer Prevention Trial (PCPT) has found that finasteride improves the performance characteristics of prostate-specific antigen (PSA) blood test as a screening tool for prostate cancer, for both cancer detection as well as for detection of high risk disease. Finally, 5AR inhibitors have been studied as a component of multimodal therapy for all stages of prostate cancer, with the goal of improving oncologic outcomes while avoiding the toxicity of medical and surgical castration.

To assess the relationship between 5α-reductase inhibitors (5ARIs) and the risk of male breast cancer (MBC).

The primary aim of this study was to evaluate if exposure to 5-alpha-reductase inhibitors (5-ARIs) modifies the effect of MRI for the diagnosis of clinically significant Prostate Cancer (csPCa) (ISUP Gleason grade ≥ 2).

In vertebrates, the steroidogenesis enzyme 5α-reductase converts testosterone to the more potent androgen 5α-dihydrotestosterone. Homologues of 5α-reductase genes have been identified in molluscs. However, recent findings suggest that vertebrate-type steroid androgens are not utilised in molluscan reproductive development. Genomic searches have revealed that molluscs do not possess many of the steroidogenic enzymes required to make testosterone, nor a nuclear androgen receptor. Consequently, the role of 5α-reductase in molluscs presents a mystery. Here, developmental exposures of Biomphalaria glabrata to selective pharmaceutical 5α-reductase inhibitors elicited a strong, highly reproducible phenotypic response characterised by the development of elongated "banana-shaped" shell morphology. In comparison to untreated snails, the shells are open-coiled and the whorls are unattached. Dutasteride (5α-reductase inhibitor) is approximately 10-times more potent at provoking the banana-shaped shell phenotype than finasteride, paralleling the pharmaceuticals' efficacy in humans. Other enzyme inhibitors with different modes of action were tested to investigate the specificity of the phenotype. However, only the pharmaceutical 5α-reductase inhibitors provoked the response. Dutasteride elicited the same phenotype in a second gastropod, Physella acuta. In the absence of evidence for de novo androgen steroidogenesis in molluscs, these findings suggest that novel substrates for 5α-reductase exist in gastropods, lending support to the contention that molluscan endocrinology differs from the well-characterised vertebrate endocrine system.

The efficacy and safety of 5α-reductase inhibitors (5ARIs) in treating prostate cancer (PCa) have not been fully determined. We performed a meta-analysis to evaluate the effectiveness and safety of 5ARIs for PCa patients.

4-Substituted N-(1,1-dimethylethyl)-3-oxo-4-androstene-17 beta-carboxamides with the hydroxy (OH) 3d, mercapto (SH) 3e, chloro (Cl) 3f, and bromo (Br) 3g substituents at the 4-position were prepared in a two-step sequence with overall yields of 21%, 27%, 41%, and 37%, respectively. Compounds 3d-g showed weak inhibitory activity on human type I 5 alpha-reductase (IC50 > or = 700 nM) while they had intermediate inhibitory activity on human type II 5 alpha-reductase at IC50S of 172, 437, 192, and 387 nM, respectively. In androgen-sensitive Shionogi cells, the inhibition of dihydrotestosterone (DHT) stimulatory action on the proliferation of the androgen-sensitive cancer cells by all four compounds was high at IC50S of 170-279 nM compared with 117 nM for hydroxyflutamide. The present data show compounds having both moderate inhibition of human type II 5 alpha-reductase activity and relatively potent antiandrogenic action, two beneficial characteristics in the therapy of androgenic-sensitive diseases.

Although combination therapy with 5 alpha-reductase inhibitor (5ARI) and alpha-blocker is one of the standard interventions in symptomatic benign prostatic hyperplasia (BPH), 5ARI monotherapy is seldom the focus of attention. Adverse events associated with 5ARI include depression and suicidal attempts in addition to persistent erectile dysfunction. The aim of this study is to update our knowledge of clinical efficacy and incidence of adverse events associated with 5ARI treatment in symptomatic BPH.

The incidence of bladder cancer (BCa) is approximately four times higher in men than in women. To develop effective BCa treatments, there is an urgent need to understand the differences in the BCa control mechanisms based on gender. Our recent clinical study showed that androgen suppression therapy using 5α-reductase inhibitors and androgen deprivation therapy affects BCa progression, but the underlying mechanisms are still unknown.

5-alpha reductase inhibitors can reduce the risk of prostate cancer (PCa) but can be associated with significant side effects. A library of nomograms which predict the risk of clinical endpoints relevant to dutasteride treatment may help determine if chemoprevention is suited to the individual patient.

The use of the 5-alpha reductase inhibitors (5-ARIs) finasteride and dutasteride for prostate cancer prevention is still under debate. The FDA recently concluded that the increased prevalence of high-grade tumors among 5-ARI-treated patients must not be neglected, and they decided to disallow the use of 5-ARIs for prostate cancer prevention. This study was conducted to verify the effects of finasteride on prostate cell migration and invasion and the related enzymes/proteins in normal human and tumoral prostatic cell lines.

Medical treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic obstruction (BPO) targets prostate size, to prevent disease progression, and prostate smooth muscle tone for rapid relieve of LUTS. Holmium laser enucleation of the prostate (HoLEP) is a size-independent method for surgical treatment of LUTS/BPO in medication-refractory patients and offers durable long-term results with reduced perioperative morbidity. As up to 50% of patients receive medical treatment for LUTS/BPO prior to surgery, we analyzed the impact of alpha-blockers and 5-alpha reductase inhibitors (5-ARI) on outcomes and perioperative morbidity in patients undergoing HoLEP for LUTS.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has led to a global health crisis, and yet our understanding of the disease pathophysiology and potential treatment options remains limited. SARS-CoV-2 infection occurs through binding and internalization of the viral spike protein to angiotensin converting enzyme 2 (ACE2) on the host cell membrane. Lethal complications are caused by damage and failure of vital organs that express high levels of ACE2, including the lungs, the heart and the kidneys. Here, we established a high-throughput drug screening strategy to identify therapeutic candidates that reduce ACE2 levels in human embryonic stem cell (hESC) derived cardiac cells. Drug target analysis of validated hit compounds, including 5 alpha reductase inhibitors, revealed androgen signaling as a key modulator of ACE2 levels. Treatment with the 5 alpha reductase inhibitor dutasteride reduced ACE2 levels and internalization of recombinant spike receptor binding domain (Spike-RBD) in hESC-derived cardiac cells and human alveolar epithelial cells. Finally, clinical data on coronavirus disease 2019 (COVID-19) patients demonstrated that abnormal androgen states are significantly associated with severe disease complications and cardiac injury as measured by blood troponin T levels. These findings provide important insights on the mechanism of increased disease susceptibility in male COVID-19 patients and identify androgen receptor inhibition as a potential therapeutic strategy.

Chronic inflammation of the hair follicle (HF) is considered a contributing factor in the pathogenesis of androgenetic alopecia (AGA). Previously, we clinically tested liposterolic extract of Serenoa repens (LSESr) and its glycoside, β-sitosterol, in subjects with AGA and showed a highly positive response to treatment. In this study, we sought to determine whether blockade of inflammation using a composition containing LSESr as well as two anti-inflammatory agents (carnitine and thioctic acid) could alter the expression of molecular markers of inflammation in a well-established in vitro system. Using a well-validated assay representative of HF keratinocytes, specifically, stimulation of cultured human keratinocyte cells in vitro, we measured changes in gene expression of a spectrum of well-known inflammatory markers. Lipopolysaccharide (LPS) provided an inflammatory stimulus. In particular, we found that the composition effectively suppressed LPS-activated gene expression of chemokines, including CCL17, CXCL6 and LTB(4) associated with pathways involved in inflammation and apoptosis. Our data support the hypothesis that the test compound exhibits anti-inflammatory characteristics in a well-established in vitro assay representing HF keratinocyte gene expression. These findings suggest that 5-alpha reductase inhibitors combined with blockade of inflammatory processes could represent a novel two-pronged approach in the treatment of AGA with improved efficacy over current modalities.

Bladder cancer (BCa) is an endocrine-related tumour and the activation of androgen signalling pathways may promote bladder tumorigenesis. We summarized the available preclinical and clinical evidence on the implications of the manipulation of androgen signalling pathways on the outcomes of BCa therapies. A systematic review was performed in December 2020. We included papers that met the following criteria: original preclinical and clinical research; evaluating the impact of androgen signalling modulation on the outcomes of BCa therapies. Six preclinical and eight clinical studies were identified. The preclinical evidence demonstrates that the modulation of androgen receptor-related pathways has the potential to interfere with the activity of the Bacillus Calmette Guerin, doxorubicin, cisplatin, gemcitabine, and radiotherapy. The relative risk of BCa recurrence after transurethral resection of the bladder tumour (TURBT) is significantly lower in patients undergoing therapy with 5 alpha reductase inhibitors (5-ARIs) or androgen deprivation therapy (ADT) (Relative risk: 0.50, 95% CI: 0.30-0.82; p = 0.006). Subgroup analysis in patients receiving 5-ARIs revealed a relative risk of BCa recurrence of 0.46 (95% CI: 0.22-0.95; p = 0.040). A significant negative association between the ratio of T1 BCa patients in treated/control groups and the relative risk of BCa recurrence was observed. Therapy with 5-ARIs may represent a potential strategy aimed at reducing BCa recurrence rate, mainly in patients with low stage disease. Further studies are needed to confirm these preliminary data.

Patients suffering from recurrent or metastatic (R/M) salivary duct carcinoma (SDC) are often treated with combined androgen blockade (CAB). However, CAB frequently fails, resulting in a worse prognosis. Therefore, biomarkers that can predict treatment failure are urgently needed. mRNA from 76 R/M androgen receptor (AR)-positive SDC patients treated with leuprorelin acetate combined with bicalutamide was extracted from pre-treatment tumor specimens. AR, Notch, MAPK, TGFβ, estrogen receptor (ER), Hedgehog (HH), and PI3K signaling pathway activity scores (PAS) were determined based on the expression levels of target genes. Additionally, 5-alpha reductase type 1 (SRD5A1) expression was determined. These markers were related to clinical benefit (complete/partial response or stable disease ≥6 months) and progression-free and overall survival (PFS/OS). SRD5A1 expression had the highest general predictive value for clinical benefit and positive predictive value (PPV: 85.7%). AR PAS had the highest negative predictive value (NPV: 93.3%). The fitting of a multivariable model led to the identification of SRD5A1, TGFβ, and Notch PAS as the most predictive combination. High AR, high Notch, high ER, low HH PAS, and high SRD5A1 expression were also of prognostic importance regarding PFS and SRD5A1 expression levels for OS. AR, Notch PAS, and SRD5A1 expression have the potential to predict the clinical benefit of CAB treatment in SDC patients. SRD5A1 expression can identify patients that will and AR PAS patients that will not experience clinical benefit (85.7% and 93.3% for PPV and NPV, respectively). The predictive potential of SRD5A1 expression forms a rational basis for including SRD5A1-inhibitors in SDC patients' treatment.

A wide array of drugs are available for the treatment of lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH), but the evidence for the comparative effectiveness is controversial.The objective of this study is to evaluate the comparative effectiveness and safety of monodrug therapies for BPH.Data sources are MEDLINE, EMBASE, and the Cochrane Library.We included randomized controlled trials that compared α-blockers, 5-alpha reductase inhibitors (5ARIs), muscarinic receptor antagonists (MRAs), phosphodiesterase-5 inhibitor (PDE5-Is), or placebo for the treatment of BPH.Comparative effectiveness and safety were pooled by both traditional meta-analysis and network meta-analysis. Summary effect size was calculated as mean difference (MD) and relative risk (RR), together with the 95% confidence intervals (CIs).This study included 58,548 participants from 124 trials in total. When compared with placebo, α-blockers, 5ARIs, and PDE5-Is reduced International Prostate Symptom Score (IPSS) by -1.35 to -3.67 points and increased peak urinary flow rate (PUF) by -0.02 to 1.95 mL/s, with doxazosin (IPSS: MD, -3.67[-4.33 to -3.02]; PUF: MD, 1.95[1.61 to 2.30]) and terazosin (IPSS: MD, -3.37 [-4.24 to -2.50]; PUF: MD, 1.21[0.74 to 1.66]) showing the greatest improvement. The improvement in the IPSS was comparable among tamsulosin, alfuzosin, naftopidil, silodosin, dutasteride, sildenafil, vardenafil, and tadalafil. The incidence of total adverse events and withdraws due to adverse events were generally comparable among various agents.In conclusion, α-blockers, 5ARIs, and PDE5-Is are effective for BPH, with doxazosin and terazosin appearing to be the most effective agents. Drug therapies for BPH are generally safe and well-tolerated, with no major difference regarding the overall safety profile.