Finasteride: The First 5α-Reductase Inhibitor

Post-finasteride syndrome - a true clinical entity?

This review critically examines Post-Finasteride Syndrome (PFS), a condition eventually reported by men who have used finasteride for androgenetic alopecia or benign prostatic enlargement and experienced persistent adverse effects after discontinuation. We explore the clinical manifestations, including sexual dysfunction, neuropsychiatric symptoms, and physical changes, that collectively challenge both diagnosis and management. This review evaluates the evidence for PFS, discusses potential mechanisms including neurobiological alterations, genetic predispositions, and addresses the controversies surrounding its existence and recognition by the medical community. Emphasis is placed on the role of patient education and the need for thorough risk assessment before prescribing finasteride. Although contrasting data from literature, men treated with finasteride could develop a plethora of non-neglectable physical and psychological symptoms identifying PFS. A multidisciplinary approach to research, policy-making, and patient advocacy is essential to better understand, diagnose, and manage PFS, underlining the necessity for greater awareness and scientific inquiry into this contentious and impactful syndrome.

Finasteride delays atherosclerosis progression in mice and is associated with a reduction in plasma cholesterol in men

Finasteride is commonly prescribed to treat benign prostate hyperplasia and male-pattern baldness in cis men and, more recently, trans individuals. However, the effect of finasteride on cardiovascular disease remains elusive. We evaluated the role of finasteride on atherosclerosis using low-density lipoprotein (LDL) receptor-deficient (Ldlr-/-) mice. Next, we examined the relevance to humans by analyzing the data deposited between 2009 and 2016 in the National Health and Nutrition Examination Survey. We show that finasteride reduces total plasma cholesterol and delays the development of atherosclerosis in Ldlr-/- mice. Finasteride reduced monocytosis, monocyte recruitment to the lesion, macrophage lesion content, and necrotic core area, the latter of which is an indicator of plaque vulnerability in humans. RNA sequencing analysis revealed a downregulation of inflammatory pathways and an upregulation of bile acid metabolism, oxidative phosphorylation, and cholesterol pathways in the liver of mice taking finasteride. Men reporting the use of finasteride showed lower plasma levels of cholesterol and LDL-cholesterol than those not taking the drug. Our data unveil finasteride as a potential treatment to delay cardiovascular disease in people by improving the plasma lipid profile.

Evaluation of the therapeutic effects of AGA drugs by measuring finasteride, dutasteride, and dihydrotestosterone in hair

BACKGROUND

Androgenetic alopecia (AGA) is treated by 5α-reductase inhibitors (5ARI) such as finasteride and dutasteride, which are widely used as therapeutic agents. However, their pharmacokinetics in target organs (scalp and hair follicles) have not yet been investigated.

PURPOSE

To confirm the effective action of finasteride and dutasteride in the hair follicle tissues, we developed a method to measure these concentrations in hair.

RESULTS

Compared to the non-detection (N.D.) group, the dihydrotestosterone (DHT) concentrations decreased significantly in both the finasteride and dutasteride groups. The dutasteride group showed significantly lower DHT concentrations among all groups.

CONCLUSIONS

Measurement of finasteride, dutasteride, and DHT concentrations in hair would aid in evaluating the drug pharmacokinetics and its therapeutic effects on AGA patients.

Dietary marine-derived ingredients for stimulating hair cell cycle

In normal condition human hair growth occurs through three phases, anagen (growth phase included about 85 % of hairs, last from 2 to 6 years), catagen (transitional phase lasting up to 2 weeks) and telogen (resting phase which last from 1 to 4 months). Natural dynamics of the hair growth process can be impaired by several factors, such as genetic predisposition, hormonal disorders, aging, poor nutrition or stress, which can lead to the slowdown in the growth of hair or even hair loss. The aim of the study was to assess the hair growth promotion effect of marine-derived ingredients, hair supplement Viviscal® and its raw components (marine protein complex AminoMarC®, shark and oyster extract). Cytotoxicity, production of alkaline phosphatase and glycosaminoglycans, as well as expression of genes involved in hair cycle-related pathways were investigated using dermal papilla cells, both immortalized and primary cell lines. Tested marine compounds showed no evidence of cytotoxicity under in vitro conditions. Viviscal® significantly increased proliferation of dermal papilla cells. Moreover, tested samples stimulated cells to produce alkaline phosphatase and glycosaminoglycans. Increased expression of hair cell cycle-related genes was also observed. The obtained results indicate that marine-derived ingredients stimulate hair growth through anagen activation.

Highlights on Steroidal Arylidene Derivatives as a Source of Pharmacologically Active Compounds: A Review

Steroids constitute a unique class of chemical compounds, playing an important role in physiopathological processes, and have high pharmacological interest. Additionally, steroids have been associated with a relatively low toxicity and high bioavailability. Nowadays, multiple steroidal derivatives are clinically available for the treatment of numerous diseases. Moreover, different structural modifications on their skeleton have been explored, aiming to develop compounds with new and improved pharmacological properties. Thus, steroidal arylidene derivatives emerged as a relevant example of these modifications. This family of compounds has been mainly described as 17β-hydroxysteroid dehydrogenase type 1 and aromatase inhibitors, as well as neuroprotective and anticancer agents. Besides, due to their straightforward preparation and intrinsic chemical reactivity, steroidal arylidene derivatives are important synthetic intermediates for the preparation of other compounds, particularly bearing heterocyclic systems. In fact, starting from arylidenesteroids, it was possible to develop bioactive steroidal pyrazolines, pyrazoles, pyrimidines, pyridines, spiro-pyrrolidines, amongst others. Most of these products have also been studied as anti-inflammatory and anticancer agents, as well as 5α-reductase and aromatase inhibitors. This work aims to provide a comprehensive overview of steroidal arylidene derivatives described in the literature, highlighting their bioactivities and importance as synthetic intermediates for other pharmacologically active compounds.

Pharmacological Modulation of Steroid Activity in Hormone-Dependent Breast and Prostate Cancers: Effect of Some Plant Extract Derivatives

The great majority of breast and prostate tumors are hormone-dependent cancers; hence, estrogens and androgens can, respectively, drive their developments, making it possible to use pharmacological therapies in their hormone-dependent phases by targeting the levels of steroid or modulating their physiological activity through their respective nuclear receptors when the tumors relapse. Unfortunately, at some stage, both breast and prostate cancers become resistant to pharmacological treatments that aim to block their receptors, estrogen (ER) or androgen (AR) receptors, respectively. So far, antiestrogens and antiandrogens used in clinics have been designed based on their structural analogies with natural hormones, 17-β estradiol and dihydrotestosterone. Plants are a potential source of drug discovery and the development of new pharmacological compounds. The aim of this review article is to highlight the recent advances in the pharmacological modulation of androgen or estrogen levels, and their activity through their cognate nuclear receptors in prostate or breast cancer and the effects of some plants extracts.

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.

Post-finasteride syndrome - does it really exist?

Inhibitors of 5α-steroid reductase are drugs used to treat androgen-dependent conditions including prostate diseases and androgenic alopecia. Finasteride was the first on the market and is currently the most widely used inhibitor. Dutasteride was the second inhibitor to be approved and has a similar safety profile. Common adverse events of treatment consist of sexual disorders and a negative affect balance. It was described that the prolonged use of 5α-steroid reductase inhibitors in patients with alopecia can cause persistent side effects called a post-finasteride syndrome (PFS), that is not just a simple coexistence of events, but rather a definite syndrome with an iatrogenic background. PFS occurs in susceptible individuals even after small doses of the drug and can last for a long time after the discontinuation of treatment. A deterioration in the quality of life in affected individuals does not justify use of the drug. Wider recognition of PFS symptoms, its incidence, course, prevention, and treatment possibilities will allow the indications for drug use to be reconsidered and treatment to be more personalized. Knowledge about PFS will also help to provide the best treatment for affected individuals and to properly educate patients before obtaining an informed consent for therapy with 5α-steroid reductase inhibitors.

Arrhythmogenic effect of androgens on the rat heart

In most species androgens shorten the cardiac action potential and reduce the risk of afterdepolarizations. Despite the central role of the rat model in physiological studies, the effects of androgens on the rat heart are still inconclusive. We therefore performed electrophysiological studies on the perfused rat right ventricular free wall. We found a correlation between androgenic activity and a propensity to generate ventricular ectopic action potentials. We also found that the testosterone treatment increased action potential duration at 90 % of repolarization (APD90), while androgenic inhibition increased the time to peak and decreased APD90. We observed that the voltage-gated potassium channel Kv4.3 and the bi-directional membrane ion transporter NCX in the rat myocardium were regulated by androgenic hormones. One possible explanation for these findings is that due to the expression of specific ion channels in the rat myocardium, the action potential response to its hormonal background is different from those described in other experimental models. Our results indicate that androgenic control of NCX expression plays a key role in determining arrhythmogenicity in the rat heart.

5α-Reductase inhibitors in androgenetic alopecia

PURPOSE OF REVIEW

The authors will review the current literature on efficacy and safety of 5-alpha reductase inhibitors (5αRIs) for androgenetic alopecia (AGA).

RECENT FINDINGS

The 5αRI finasteride and dutasteride are effective in treating AGA and promoting hair regrowth. 5αRI can be given orally, topically and more recently through mesotherapy. However, there has been an increasing concern about permanent sexual adverse events such as impotence and infertility. Most of these reports are published as case reports, and two studies reporting persistent sexual side-effects after discontinuation of finasteride had serious method limitations, as patients were recruited from a website. To our knowledge, permanent sexual adverse events have yet to be published in higher quality studies, such as randomized controlled trials. Although patients treated with 5αRIs have an increased incidence of sexual adverse events, these events decrease if discontinued or over time with continued therapy.

SUMMARY

Sexual side-effects are uncommon and resolve spontaneously in most patients even without discontinuing therapy. Significant effort is underway to find delivery systems that optimize delivery and reduce systemic absorption of topical 5αRs including hydroxypropyl chitosan and liposomal and nanoparticulate systems.

Steroidal pyrazolines and pyrazoles as potential 5α-reductase inhibitors: synthesis and biological evaluation

Taking pregnenolone as the starting material, two series of pyrazolinyl and pyrazolyl pregnenolones were synthesized through different routes. The synthesis of the analogs of both series is multistep and proceeds in good overall yields. While the key step in the synthesis of pyrazolinyl pregnenolones is the heterocyclization of benzylidine derivatives (3) in presence of hydrazine hydrate, it is the condensation of 3β-hydroxy-21-hydroxymethylidenepregn-5-en-3β-ol-20-one (5) with phenylhydrazine in the synthesis of pyrazolyl derivatives. Compounds of both the series were tested for their 5α-reductase inhibitory activities. Amongst all the compounds screened for their 5α-reductase inhibitory activities, compound 4b, 4c and 6b were found to be the most active.

Targeting cancer using cholesterol conjugates

Conjugation of cholesterol moiety to active compounds for either cancer treatment or diagnosis is an attractive approach. Cholesterol derivatives are widely studied as cancer diagnostic agents and as anticancer derivatives either in vitro or in vivo using animal models. In largely growing studies, anticancer agents have been chemically conjugated to cholesterol molecules, to enhance their pharmacokinetic behavior, cellular uptake, target specificity, and safety. To efficiently deliver anticancer agents to the target cells and tissues, many different cholesterol-anticancer conjugates were synthesized and characterized, and their anticancer efficiencies were tested in vitro and in vivo.

The combination of metyrapone and oxazepam for the treatment of cocaine and other drug addictions

Although scientists have been investigating the neurobiology of psychomotor stimulant reward for many decades, there is still no FDA-approved treatment for cocaine or methamphetamine abuse. Research in our laboratory has focused on the relationship between stress, the subsequent activation of the hypothalamic-pituitary-adrenal (HPA) axis, and psychomotor stimulant reinforcement for almost 30 years. This research has led to the development of a combination of low doses of the cortisol synthesis inhibitor, metyrapone, and the benzodiazepine, oxazepam, as a potential pharmacological treatment for cocaine and other substance use disorders. In fact, we have conducted a pilot clinical trial that demonstrated that this combination can reduce cocaine craving and cocaine use. Our initial hypothesis underlying this effect was that the combination of metyrapone and oxazepam reduced cocaine seeking and taking by decreasing activity within the HPA axis. Even so, doses of the metyrapone and oxazepam combination that consistently reduced cocaine taking and seeking did not reliably alter plasma corticosterone (or cortisol in the pilot clinical trial). Furthermore, subsequent research has demonstrated that this drug combination is effective in adrenalectomized rats, suggesting that these effects must be mediated above the level of the adrenal gland. Our evolving hypothesis is that the combination of metyrapone and oxazepam produces its effects by increasing the levels of neuroactive steroids, most notably tetrahydrodeoxycorticosterone, in the medial prefrontal cortex and amygdala. Additional research will be necessary to confirm this hypothesis and may lead to the development of improved and specific pharmacotherapies for the treatment of psychomotor stimulant use.

Is the Expression of Androgen Receptor Protein Associated With the Length of AC Repeats in the Type III 5-α Reductase Gene in Prostate Cancer Patients?

Purpose

Type III 5-α reductase (SRD5A3; steroid 5-α reductase 3) may be associated with the progression of prostate cancer (PCa). The aim of our study was to determine whether the length of AC repeats in the SRD5A3 gene is associated with the risk of PCa and the expression of androgen receptor (AR) protein in Korean men.

Materials and Methods

We compared the length of AC repeats in the short tandem repeat (STR) region of the SRD5A3 gene in 68 PCa patients and 81 control subjects by genotyping. A total of 55 patients in the PCa group underwent radical prostatectomy. We evaluated the expression of AR protein by using Western blotting and tested the association between the type of AC repeats in the SRD5A3 gene and AR protein expression and clinical and pathologic parameters.

Results

The short type of STR had less than 21 copies of AC repeats in the SRD5A3 gene. The SS type (short and short type) of STR of the SRD5A3 gene was 2.2 times as likely to occur in PCa patients as in controls (odds ratio, 2.21; 95% confidence interval, 1.14 to 4.31; p=0.019). However, AC repeats of the SRD5A3 gene were not associated with AR protein expression or clinical or pathologic parameters in PCa samples.

Conclusions

These results suggest that the short AC repeats of SRD5A3 polymorphism are associated with an increased risk of PCa. SRD5A3 polymorphism may contribute to a genetic predisposition for PCa.

Frontal fibrosing alopecia: a retrospective review of 19 patients seen at Duke University

BACKGROUND

Frontal fibrosing alopecia (FFA) is a type of scarring hair loss primarily observed in postmenopausal women and characterized by fronto-tempero-parietal hairline recession, perifollicular erythema, and loss of eyebrows. The incidence is unknown, but the number of women presenting with this condition has significantly increased in recent years. No effective therapy has been established.

OBJECTIVE

The purpose of this study is to present pertinent demographic and clinical findings of patients with FFA seen at an academic hair loss clinic and their responses to various therapeutic interventions.

METHODS

Patients seen at the Duke University Hair Disorders Research and Treatment Center, Durham, NC, between 2004 and 2011 who met FFA inclusion criteria and signed an informed consent form for participation in the Duke University Hair Disorders Research and Treatment Center database were included in this review.

RESULTS

Nineteen female patients with FFA met our inclusion criteria, the majority of whom were white and postmenopausal. A number of treatments, including topical and intralesional steroids, antibiotics, and immunomodulators, were used with disappointing results in most patients. However, the majority of patients on dutasteride experienced disease stabilization.

LIMITATIONS

This was a retrospective review and outside clinic records were occasionally incomplete.

CONCLUSIONS

FFA is an increasingly common form of scarring hair loss, but the origin remains unknown. Without clear understanding of the pathogenesis and evolution of this condition, it is not surprising that treatments to date have been minimally or not effective. At our institution, dutasteride was most effective in halting disease progression, although no therapy was associated with significant hair regrowth.

Synthesis and 5α-reductase inhibitory activity of C₂₁ steroids having 1,4-diene or 4,6-diene 20-ones and 4-azasteroid 20-oximes

The synthesis and evaluation of 5α-reductase inhibitory activity of some 4-azasteroid-20-ones and 20-oximes and 3β-hydroxy-, 3β-acetoxy-, or epoxy-substituted C₂₁ steroidal 20-ones and 20-oximes having double bonds in the A and/or B ring are described. Inhibitory activity of synthesized compounds was assessed using 5α-reductase enzyme and [1,2,6,7-³H]testosterone as substrate. All synthesized compounds were less active than finasteride (IC₅₀: 1.2 nM). Three 4-azasteroid-2-oximes (compounds 4, 6 and 8) showed good inhibitory activity (IC₅₀: 26, 10 and 11 nM) and were more active than corresponding 4-azasteroid 20-ones (compounds 3, 5 and 7). 3β-Hydroxy-, 3β-acetoxy- and 1α,2α-, 5α,6α- or 6α,7α-epoxysteroid-20-one and -20-oxime derivatives having double bonds in the A and/or B ring showed no inhibition of 5α-reductase enzyme.

In vivo investigation in pigs of intestinal absorption, hepatobiliary disposition, and metabolism of the 5α-reductase inhibitor finasteride and the effects of coadministered ketoconazole

The overall aim of this detailed investigation of the pharmacokinetics (PK) and metabolism of finasteride in pigs was to improve understanding of in vivo PK for this drug and its metabolites. Specific aims were to examine the effects of ketoconazole coadministration on the PK in three plasma compartments (the portal, hepatic, and femoral veins), bile, and urine and to use these data to study in detail the intestinal absorption and the liver extraction ratio and apply a semiphysiological based PK model to the data. The pigs received an intrajejunal dose of finasteride (0.8 mg/kg) either alone (n = 5) or together with ketoconazole (10 mg/kg) (n = 5) or an intravenous dose (0.2 mg/kg) (n = 3). Plasma, bile, and urine (collected from 0 to 6 h) were analyzed with ultraperformance liquid chromatography-tandem mass spectrometry. Ketoconazole increased the bioavailability of finasteride from 0.36 ± 0.23 to 0.91 ± 0.1 (p < 0.05) and the terminal half-life from 1.6 ± 0.4 to 4.0 ± 1.1 h (p < 0.05). From deconvolution, it was found that the absorption rate from the intestine to the portal vein was rapid, and the product of the fraction absorbed and the fraction that escaped gut wall metabolism was high (f(a) · F(G) ∼ 1). Interestingly, the apparent absorption rate constant (k(a)) to the femoral vein was lower than that to the portal vein, probably because of binding and distribution within the liver. The liver extraction ratio was time-dependent and varied with the two routes of administration. After intrajejunal administration, from 1 to 6 h, the liver extraction ratio was significantly (p < 0.05) reduced by ketoconazole treatment from intermediate (0.41 ± 0.21) to low (0.21 ± 0.10).

Finasteride-induced depression: new insights into possible pathomechanisms

5-alpha-reductase is involved as a rate-imitating enzyme in the metabolism of steroids. Several 5-alpha-reduced steroids such as dihydrotestosterone, allopregnanolone or tetrahydrocorticosterone have neurotrophic, neuroprotective, and anxiolytic properties. Reduced 5-alpha-reductase activity has been observed during depressive illness in humans. Finasteride inhibits 5-alpha-reductase and can robustly induce anxious and depressive behaviors in rodents. In humans finasteride treatment has been linked to an increase of depressive symptoms. A recent study reported that finasteride treatment inhibits hippocampal neurogenesis in mice. As hippocampal neurogenesis has been linked to emotional behavior, this could be of possible relevance for the pathophysiology of affective disorders. Further studies are needed to evaluate potential neuropsychiatric side effects of finasteride treatment in humans.

The influence of low dose finasteride, a type II 5α-reductase inhibitor, on circulating neuroactive steroids

BACKGROUND

Finasteride is a 5α-reductase inhibitor that has received clinical approval for the treatment of human benign prostatic hyperplasia and androgenetic alopecia. The treatment is practically without side effects, although some occasional cases of depression syndrome have been reported. 5α-Reductase is an enzyme responsible for the reduction of testosterone, progesterone or deoxycorticosterone to their 5α-reduced derivatives possessing anticonvulsant, antidepressant, and anxiolytic activity. Therefore, the formation of GABAergic neuroactive steroids is likely to be impacted by finasteride.

OBJECTIVE

The objective of the study was to show how the treatment of premature androgenetic alopecia with low doses (1 mg/day) of finasteride influences the broad spectrum of steroids with potential neuroactivity.

METHODS

A group of 12 men with premature androgenetic alopecia participated in the present study. The steroid hormone profile was determined for all individuals. Finasteride was administered for 4 months at a daily dose of 1 mg. After the treatment, the same hormonal profile was determined again.

RESULTS

5α-Reduced steroids, e.g., 5α-dihydrotestosterone, androsterone, epiandrosterone, 5α-androstene-3α,17β-diol, allopregnanolone, isopregnaolone, and some 5-ene steroids, such as dehydroepiandrosterone and pregnenolone, decreased gradually during treatment.

CONCLUSIONS

The decrease of 5α-reduced steroids, especially of allopregnanediol, dihydrotestosterone, and pregnenolone, is probably one of the factors responsible for the increased occurrence of depression in men treated with finasteride, even at low doses.

Identification of finasteride metabolites in human bile and urine by high-performance liquid chromatography/tandem mass spectrometry

The objective of this study was to further investigate the metabolism of the 5alpha-reductase inhibitor, finasteride, and to identify previously unknown phase I and phase II metabolites in vitro and in vivo in human bile and urine. Healthy volunteers were given 5 mg of finasteride, directly to the intestine, and bile and urine were collected for 3 and 24 h, respectively. A single-pass perfusion technique, Loc-I-Gut, was used for drug administration and bile collection from the proximal jejunum, distal to papilla of Vater. Incubations with human liver microsomes/S9 fractions and different cofactors were performed with finasteride and the previously known metabolites, omega-hydroxy finasteride (M1) and finasteride-omega-oic acid (M3). Liquid chromatography coupled to triple quadrupole mass spectrometry (MS) with positive/negative electrospray ionization and ion trap with MS(n) measurements were used for structural investigations and identification of metabolites. Two hydroxy metabolites of finasteride, other than M1, and one intact hydroxy finasteride glucuronide were identified in vitro and in bile and urine. The glucuronide and at least one of the hydroxy metabolites were previously unidentified. M1 and M3 were glucuronidated in vitro by specific human UDP-glucuronosyltransferases, UGT1A4 and UGT1A3, respectively. M1 glucuronide was not identified in vivo, and M3 glucuronide, an acyl glucuronide, was present in low amounts in bile from a few individuals. In conclusion, previously undescribed metabolites were identified, in vitro and in human urine and bile. Bile collection using the Loc-I-Gut technique followed by sensitive mass spectrometry analysis led to the discovery of novel, both phase I and phase II, finasteride metabolites in human bile.

Down-regulation of prostate specific antigen in LNCaP cells by flavonoids from the pollen of Brassica napus L

The pollen of Brassica napus L. has been used in China to treat benign prostatic hyperplasia (BPH) for over decades. In this study, the pollen of Brassica napus L. was extracted successively with chloroform, ethyl acetate and ethanol. The ethyl acetate extract showed strong activity in decreasing the secretion of prostate specific antigen (PSA) in LNCaP cells as compared to two other extracts, measured by ELISA with finasteride as positive control in the assay. Five flavonoids were subsequently isolated from the active extract using bioassay-guided fractionation. They were Naringenin (1); Luteolin (2); Kaempferol (3); Kaempferol 3-(3-E-p-coumaroyl-alpha-L-rhamnopyranoside) (4); and Kaempferol 3-(2,3-di-E-p-coumaroyl-alpha-L-rhamnopyranoside) (5). All these compounds inhibited PSA secretion significantly, with IC50 values in the range of 5-50 microM. Compounds 2, 4 and 5 showed moderate cytotoxicity to LNCaP cells within the active concentration range, while compounds 1 and 3 showed no cytotoxicity. Further studies on the mechanism action of these compounds were performed by evaluating their activation of estrogen receptor (ER) and antagonistic activities on androgen receptor (AR) in cell-based reporter gene assays. All compounds described here were first isolated from the pollen of Brassica napus L.

A new look at the 5alpha-reductase inhibitor finasteride

Finasteride is the first 5alpha-reductase inhibitor that received clinical approval for the treatment of human benign prostatic hyperplasia (BPH) and androgenetic alopecia (male pattern hair loss). These clinical applications are based on the ability of finasteride to inhibit the Type II isoform of the 5alpha-reductase enzyme, which is the predominant form in human prostate and hair follicles, and the concomitant reduction of testosterone to dihydrotestosterone (DHT). In addition to catalyzing the rate-limiting step in the reduction of testosterone, both isoforms of the 5alpha-reductase enzyme are responsible for the reduction of progesterone and deoxycorticosterone to dihydroprogesterone (DHP) and dihydrodeoxycorticosterone (DHDOC), respectively. Recent preclinical data indicate that the subsequent 3alpha-reduction of DHT, DHP and DHDOC produces steroid metabolites with rapid non-genomic effects on brain function and behavior, primarily via an enhancement of gamma-aminobutyric acid (GABA)ergic inhibitory neurotransmission. Consistent with their ability to enhance the action of GABA at GABA(A) receptors, these steroid derivatives (termed neuroactive steroids) possess anticonvulsant, antidepressant and anxiolytic effects in addition to altering aspects of sexual- and alcohol-related behaviors. Thus, finasteride, which inhibits both isoforms of 5alpha-reductase in rodents, has been used as a tool to manipulate neuroactive steroid levels and determine the impact on behavior. Results of some preclinical studies and clinical observations with finasteride are described in this review article. The data suggest that endogenous neuroactive steroid levels may be inversely related to symptoms of premenstrual and postpartum dysphoric disorder, catamenial epilepsy, depression, and alcohol withdrawal.

Comparative pharmacophore development for inhibitors of human and rat 5-alpha-reductase

There are a number of diseases where the 5-alpha-reductase (5AR) enzyme is of therapeutic interest as a drug target. Currently the crystal structure for 5-alpha-reductase is unavailable, thus ligand-based pharmacophore techniques are beneficial in the drug development process. We have developed pharmacophores to aid inhibitor design for both human types I (preliminary) and II 5-alpha-reductase isozymes and also the rat type II isozyme. To our knowledge, these are the first published pharmacophores for inhibitors of the human type I and rat type II enzymes. A comparison between isozymes and the previously published human type II isozyme pharmacophore is also presented.

Pharmacokinetics and pharmacodynamics of TF-505, a novel nonsteroidal 5alpha-reductase inhibitor, in normal subjects treated with single or multiple doses

AIMS

To assess the tolerability, pharmacokinetics and pharmacodynamics of a novel nonsteroidal and noncompetitive inhibitor of type I and type II 5alpha-reductases, (-)-(S)-4-[1-[4-[1-(4-isobutylphenyl) butoxy]benzoyl]indolizin-3-yl]butyric acid (TF-505), after single and multiple oral doses in healthy volunteers.

METHODS

In the single-dose study, six young adult males in each dose group received 25 mg or 50 mg of TF-505, and six older males (>or= 40 years) in each dose group received 75 mg or 100 mg of TF-505. The subjects were given the drug in ascending dose and in the fasting state. Six subjects also received 50 mg of TF-505 after breakfast in a two-period crossover manner. In the multiple-dose study, six older males in each dose group received 12.5 mg or 25 mg TF-505 after breakfast daily for 7 days. Plasma concentrations of TF-505, dihydrotestosterone (DHT) and testosterone were measured. The pharmacokinetics of TF-505 were analysed by a compartment model with first-order absorption, first-order elimination and a lag time. Pharmacokinetic and pharmacodynamic relationships were evaluated by indirect response modelling with inhibition of input.

RESULTS

Maximum plasma concentration (Cmax) and the area under the concentration-time curve (AUC) increased proportionately after the single dose up to 50 mg and with the multiple doses. Linearity was not detected between 75 and 100 mg of TF-505. Dose dependency was also noted for the effect of TF-505 on DHT concentrations following single doses up to 50 mg and multiple doses. Plasma DHT concentrations decreased maximally to 58.2, 49.5, 54.2 and 49.8% of basal values at 8-12 h after single administration of 25, 50, 75 and 100 mg TF-505, respectively, and to 60.5 and 49.4% at the 7th and 5th dose following multiple doses of 12.5 and 25 mg TF-505, respectively. The predicted effect curves matched the observed data when the indirect response model was applied to the time course of the suppressant effect of TF-505 on plasma DHT concentrations after both the single and multiple studies. Fifty percent inhibitory concentrations (IC50) of 0.82, 1.48, 1.31 and 0.88 micro g ml(-1), zero-order rate constants for the onset of plasma DHT concentration changes (kin) of 17.8, 17.4, 17.0 and 10.7% h(-1) and first-order rate constants for increase in plasma DHT concentrations to basal values (kout) of 0.17, 0.16, 0.17 and 0.10 h(-1) for the single study at doses of 25, 50, 75 and 100 mg, respectively, were attained. In the multiple-dose study, IC50s were 1.74 and 1.49 micro g ml(-1) for the 12.5 and 25 mg doses, respectively. No serious adverse events related to TF-505 were observed.

CONCLUSIONS

TF-505 was well tolerated in healthy male volunteers. Accumulation of TF-505 in plasma was not observed during multiple dosing. The indirect response model described the relationships between pharmacokinetics and pharmacodynamics of TF-505. Such modelling is expected to yield an appropriate dosage regimen in subsequent clinical trials.

Comparison of Diane 35 and Diane 35 plus finasteride in the treatment of hirsutism

OBJECTIVE

To compare the clinical efficacy and safety of the combination of Diane 35 (2 mg of cyproterone acetate, and 35 microg of ethinyl estradiol) plus finasteride (5 mg), and Diane 35 alone in the treatment of hirsutism.

DESIGN

Prospective randomized clinical study.

SETTING

Outpatients in Erciyes University Medical School.

PATIENT(S)

Forty women with hirsutism were selected.

INTERVENTION(S)

For 1 year, group 1 patients (n = 20) were treated with Diane 35 alone (2 mg of cyproterone acetate and 35 microg of ethinyl estradiol) daily on days 5 to 25 of the menstrual cycle and group 2 patients (n = 20) with Diane 35 plus finasteride (5 mg daily).

MAIN OUTCOME MEASURE(S)

Hirsutism was graded at 6-month intervals using the Ferriman-Gallwey method. The basal hormone levels of total and free testosterone (T), androstenedione, DHEAS, and sex-hormone-binding globulin (SHBG) were measured by radioimmunoassay before the study. Total T, free T, SHBG, and DHEAS were also measured at 6-month intervals for 1 year. Multiscreen blood chemistry and side effects were evaluated during the treatment.

RESULT(S)

Thirty-four patients completed the 12-month study period. A significant decrease in the hirsutism score as compared to baseline was observed after 12 months with both Diane 35 treatment (mean +/- SD, 15.62 +/- 4.89 vs. 9.75 +/- 3.97) and Diane 35 plus finasteride treatment (16.27 +/- 6.90 vs. 8.38 +/- 4.44). The percentage decreases in the hirsutism score (mean percent +/- SD) were 30.26 +/- 14.56 vs. 34.70 +/- 11.60 at 6 months, 38.09 +/- 11.46 vs. 48.14 +/- 14.27 at 12 months in the Diane 35 and the Diane 35 plus finasteride groups, respectively. The percentage reduction in the hirsutism score in the Diane 35 plus finasteride group at 12 months was greater than in the Diane 35 group (P <.05).

CONCLUSION(S)

The percentage decrease in the hirsutism score at 12 months was higher in the Diane 35 plus finasteride group than in the Diane 35 group. We believe that Diane 35 plus finasteride is an effective and safe combination for the treatment of hirsutism.

Biochemical roles of testosterone and epitestosterone to 5 alpha-reductase as indicators of male-pattern baldness

In establishing a theory to predict male-pattern baldness, we investigated the correlation of testosterone, epitestosterone, and dihydrotestosterone with 5alpha-reductase in hair using gas chromatography-mass spectrometry. One hundred milligram hair samples were obtained from a group of balding subjects and their sons, as well as from a corresponding aged-matched, nonbalding group. The ratio of testosterone to epitestosterone was significantly greater (mean 46.41, p < 0.001; mean 35.83, p < 0.001, respectively) in the hair of balding fathers (n = 19, age 28-50 y) and their sons (n = 16, age 8-16 y) than in the hair of the nonbalding control subjects (mean 9.17 and 10.47, respectively). These findings demonstrate that analysis of terminal hair may not only provide a basis for predicting baldness when the subject is still young, but also for preventing and treating male-pattern baldness by controlling the steroid hormone balance.

Alterations of prostate biomarker expression and testosterone utilization in human LNCaP prostatic carcinoma cells by garlic-derived S-allylmercaptocysteine

BACKGROUND

This study determined the effects of S-allylmercaptocysteine (SAMC), a phytoconstituent from garlic, on the expression of androgen-responsive biomarkers, prostate specific antigen (PSA), and prostate specific membrane antigen (PSMA), in human prostatic carcinoma cells (LNCaP).

METHODS

Secretion of PSA was determined as well as the activity of PSMA measured as a function of its ability to hydrolyze poly-gamma-glutamated folate and N-acetylaspartylglutamate (NAAG). Folate hydrolase capacity was also determined in SAMC-treated cells grown in charcoal stripped fetal calf serum (CS-FCS). In addition, testosterone disappearance was measured from culture media of SAMC-treated LNCaP and PC-3 cells as well as from cell free lysates.

RESULTS

PSA secretions were significantly decreased compared to control values at 1 day (8.4 +/- 2.6 vs. 18.9 +/- 1.7, P < 0.01), 4 days (18.9 +/- 5.3 vs. 73.8 +/- 4. 4, P < 0.001), and 6 days (35.6 +/- 2.1 vs. 96.5 +/- 17.9 ng/10(5) cells, P < 0.01; mean +/- SD). By contrast, PSMA activity measured as either folate hydrolase or NAAG dipeptidase (NAALADase) activity increased in cells treated with SAMC. PSMA-folate hydrolase activity in SAMC-treated cells grown in CS-FCS increased beyond that observed in cells grown in CS-FCS alone. Pre-exposure of LNCaP cells to SAMC resulted in enhanced rate of testosterone disappearance from culture media at 6 hr (P < 0.01) and at 48 hr (P < 0.001) compared to media from cells not previously exposed to SAMC. Results similar to these were also observed in androgen-independent PC-3 cells treated with SAMC. In lysates of SAMC-treated LNCaP cells, the rate of testosterone catabolism was twice that from phosphate buffered saline (PBS)-treated cells. SAMC-treated LNCaP cells grown in media supplemented with testosterone temporarily exhibited enhanced growth over a 2 day period but cell numbers declined later to levels similar to those of SAMC treatment.

CONCLUSIONS

These results show that SAMC exhibits differential effects on recognized biomarkers for LNCaP cells similar to those produced by androgen deprivation and strongly suggests that this effect may be mediated, in part, by diminishing the trophic effects of testosterone, likely by converting it to metabolites less reactive toward androgen receptors.

Improvement in androgenetic alopecia in 53-76-year-old men using oral finasteride

Twenty-eight men with AGA, aged 53-76 years (mean, 65 years), were selected to participate in this trial from a double blind, placebo controlled, multicenter study of subjects with moderate symptoms of BPH. Patients received either finasteride 5 mg or placebo daily for 24 months. Hair counts were performed at entry to the study and at 6, 12, 18, and 24 months. Hair counts were made directly on the scalp in a circular target area 1 in in diameter, located in the center of a template. The template was applied in such a way that its counting window fell on the most balding scalp area, which remained the same for each patient.11 At each hair counting session, patients were asked about side-effects and questioned about their sex life. Time trend and differences between groups were examined using a one-way (treatment) MANOVA with repeated measures (baseline, 6, 12, 18, and 24 months). Additional two-tailed t-tests were performed to compare the two groups at each point of time. P < 0.05 was considered to be significant.

Comparison of cyproterone acetate plus ethinyl estradiol and finasteride in the treatment of hirsutism

The aim of this study was to compare the clinical efficacy and safety of low dose cyproterone acetate-estrogen combination (Diane) and the 5 alpha-reductase inhibitor finasteride in the treatment of hirsutism. Fourty-two women with hirsutism were included in the study. Twenty-one patients treated with cyproterone acetate (CPA) 2 mg and ethinyl estradiol (E) 35 micrograms daily on days 5-25 of the menstrual cycle, 21 with finasteride 5 mg daily. Hirsutism score, hormone levels, multiscreen blood chemistry and side effects were evaluated at three-monthly intervals for 9 months. A significant decrease in hirsutism score as compared to baseline was observed after 9 months with either CPA + E (Diane) (mean +/- SE, 15.81 +/- 1.19 vs 8.38 +/- 1.21) or finasteride treatment (17.81 +/- 1.05 vs 10.86 +/- 0.91) (p < 0.0005). The reductions in hirsutism scores (mean% +/- SE) were 14.23 +/- 2.29 vs 19.77 +/- 2.22 (p < 0.05) at 3, 40.23 +/- 4.58 vs 29.49 +/- 2.69 (p < 0.02) at 6 and 50.99 +/- 4.13 vs 39.87 +/- 3.30 (p < 0.02) at 9 months in CPA + E and finasteride groups, respectively. No significant changes were observed in hormone levels during finasteride treatment. Serum free testosterone significantly decreased at the third month of treatment, and remained suppressed for the duration of treatment in CPA + E group. DHEAS levels also decreased significantly after 6 and 9 months of therapy with CPA + E. SHBG significantly increased during CPA + E treatment. We conclude that both drugs are effective and well tolerated, but CPA + E appears to be more effective than 5 alpha-reductase inhibitor finasteride in long-term treatment of hirsute women. Diane is also a cost-effective drug.

Assessment of the pharmacokinetic-pharmacodynamic interaction between terazosin and finasteride

The pharmacokinetic-pharmacodynamic interaction between terazosin and finasteride was evaluated in an 18-day, parallel, open-label, randomized study. Forty-eight non-smoking, healthy, adult male volunteers entered the study. One third of the participants received terazosin alone, one third received terazosin and finasteride, and one third received finasteride alone. Multiple-dose coadministration of terazosin and finasteride did not alter the central values of steady-state pharmacokinetic parameters of either drug in a statistically significant manner. Compared with the single-agent groups, however, the group taking finasteride and terazosin had higher variability in the pharmacokinetic parameters of both drugs. Testosterone concentrations were not altered after administration of finasteride and terazosin alone or in combination. Terazosin administered alone did not affect the dihydrotestosterone concentrations. The significant reduction in dihydrotestosterone concentrations induced by administration of finasteride was not affected by coadministration of terazosin. Mean changes in blood pressure and pulse rate in these normotensive volunteers were generally slight; therefore, concurrent administration of multiple doses of terazosin and finasteride did not produce significant clinical concern.

Finasteride inhibits 5 alpha-reductase activity in human dermal fibroblasts: prediction of its therapeutic application in androgen-related skin diseases

BACKGROUND

The potential role of finasteride in treating androgen related skin disorders was investigated.

METHODS

Pooled human dermal fibroblasts were used to assess the effect of finasteride on the 5 alpha-reductase activity in skin tissue. Vmax and Km were estimated in the presence of 0, 10, and 200 nM finasteride.

RESULTS

Vmax values remain constant near 1.20 pmol/mg protein/h in the presence of increasing concentrations of finasteride; however, apparent Km increases from 0.27 nM at 0 nM finasteride to 0.31 nM and 0.44 nM at 10 nM and 200 nM finasteride, respectively. This suggests that finasteride competes with testosterone and has a high affinity for same binding site of the 5 alpha-reductase enzyme. Apparent Ki was estimated at 282 nM, indicating that a high concentration of finasteride is required to significantly suppress the enzyme activity.

CONCLUSIONS

This study confirms that finasteride inhibits the conversion of testosterone to dihydrotestosterone in human reticular dermal fibroblasts. Finasteride may have therapeutic potential in treating skin disorders influenced by the action of dihydrotestosterone.