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PubMed1993

Androgen metabolism in men receiving finasteride before prostatectomy.

Oral administration of finasteride, a 5 alpha-reductase inhibitor, affects intraprostatic androgens by suppressing dihydrotestosterone and increasing testosterone. This study was designed to determine the correlation of these effects of finasteride with changes in serum dihydrotestosterone, testosterone and androstanediol glucuronide. In a double blind, placebo-controlled study, 27 men with symptomatic benign prostatic hyperplasia were treated with placebo or 1 or 5 mg. per day finasteride for 6 to 8 weeks before transurethral resection of the prostate. There was no significant change in serum testosterone in any group, or in serum dihydrotestosterone or androstanediol glucuronide in the placebo group. There was a decrease in serum dihydrotestosterone by 66 +/- 4% and 70 +/- 8% (p = 0.32), and of serum androstanediol glucuronide by 78 +/- 3% and 86 +/- 3% (p = 0.012) in the 1 and 5 mg. finasteride groups, respectively. Intraprostatic dihydrotestosterone in the placebo group decreased from 18.6 +/- 1.4 nmol./kg. to 3.8 +/- 1.0 nmol./kg. and 1.7 +/- 0.7 nmol./kg. with 1 mg. and 5 mg. finasteride, respectively (p = 0.049 between 1 mg. and 5 mg. finasteride). Intraprostatic testosterone in the placebo group increased from 1.1 +/- 0.2 nmol./kg. to 7.6 +/- 1.0 nmol./kg. and 8.3 +/- 0.7 nmol./kg. with 1 mg. and 5 mg. finasteride, respectively (no significant difference between 1 mg. and 5 mg. finasteride). Serum and intraprostatic dihydrotestosterone correlated (p = 0.002). There was no correlation between intraprostatic dihydrotestosterone and serum androstanediol glucuronide. We conclude that 5 mg. of finasteride cause greater inhibition of intraprostatic 5 alpha-reductase than 1 mg. and that serum dihydrotestosterone is a better marker of intraprostatic dihydrotestosterone than androstanediol glucuronide.

Androstane-3,17-diol↗
PubMed1995

Treatment with finasteride following radical prostatectomy for prostate cancer.

OBJECTIVES: The objective of this study was to evaluate the effect of finasteride (10 mg/d) or placebo on serum prostate-specific antigen (PSA) and recurrence rates in men with detectable PSA levels after radical prostatectomy. METHODS: A total of 120 men, 48 to 89 years old, previously treated with radical prostatectomy for prostate cancer within the past 10 years, with serum PSA levels between 0.6 and 10.0 ng/mL, with no evidence of skeletal metastasis on bone scan, and with no previous androgen deprivation therapy, were treated with 10 mg finasteride or placebo in a double-blind fashion for 12 months. After the first year, all patients were treated with finasteride for an additional 12 months. Primary endpoints were serum PSA levels and recurrence rates defined as positive bone scan or positive biopsy. RESULTS: Patients treated with finasteride had a delayed increase in serum PSA compared with placebo of approximately 9 months in the first year and 14 months by the end of the second year. Patients with baseline PSA levels less then 1.0 ng/mL had no significant increase in serum PSA during the 2 years of treatment. Fewer recurrences were observed in the finasteride group, but these differences were not statistically significant. Finasteride was well tolerated, and side effects were balanced between treatment groups. CONCLUSIONS: The results of this study indicate that treatment with finasteride delays but does not prevent the rise in serum PSA observed in untreated patients with detectable PSA levels after radical prostatectomy. The reduction in local and distant recurrences in the finasteride group suggests that the effect on PSA reflects a direct effect on tumor growth without affecting the initial response to subsequent hormonal therapy. These data require confirmation by studies that are longer and larger, focused on demonstrating significant differences in progression rates and survival before the use of finasteride can be considered as an option for men with detectable PSA levels after radical prostatectomy.

Aged↗
PubMed1994

Effects of finasteride, a 5 alpha-reductase inhibitor, on circulating androgens and gonadotropin secretion in hirsute women.

An oral 5-mg dose of finasteride, a 5 alpha-reductase inhibitor, was administered for 3 months to 10 hirsute women to determine the effect on gonadotropin secretion, on basal and stimulated androgen secretion, and on hair growth. Hair growth was assessed by the Ferriman-Gallwey score. All of the above determinations were evaluated before and after 1 and/or 3 months of finasteride treatment. Basal and GnRH-stimulated gonadotropin secretions were not affected. Indeed, finasteride did not modify the pulsatility of LH secretion. No change was seen in estradiol, PRL, free testosterone, androstenedione, dehydroepiandrosterone sulfate, and sex hormone-binding globulin concentrations. Serum concentrations of cortisol (F) were significantly reduced after 1 month of finasteride treatment. The F levels returned to pretreatment levels after 3 months. Plasma levels of dihydrotestosterone and 3 alpha-androstanediol glucuronide significantly decreased during finasteride treatment. A significant increase in testosterone concentrations was observed after 3 months. Finasteride did not modify the responses of testosterone, androstenedione, and dehydroepiandrosterone sulfate to ACTH-(1-24) injection. Conversely, finasteride blunted the F response to corticotropin stimulation. Three months of finasteride treatment significantly decreased the Ferriman-Gallwey score. In conclusion, finasteride significantly decreased dihydrotestosterone and hair growth in hirsute women without negatively affecting gonadotropin secretion.

5-alpha Reductase Inhibitors↗
PubMed1996

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.

Adrenergic alpha-Antagonists↗
PubMed1994

5 alpha-reductase inhibition by finasteride (Proscar) in epithelium and stroma of human benign prostatic hyperplasia.

Finasteride is a specific 5 alpha-reductase inhibitor that has been shown to reduce the size of human benign prostatic hyperplasia (BPH) by inhibiting the intraprostatic conversion of testosterone to 5 alpha-dihydrotestosterone. The aim of the present in vitro study was to describe in more detail the inhibitory effect of finasteride on 5 alpha-reductase in epithelium and stroma of human BPH. 5 alpha-Reductase activity in epithelium and stroma was inhibited dose-dependently by finasteride. The mean IC50 (50% inhibitory concentration) values, determined in the presence of various testosterone concentrations, were generally 2- to 4-fold lower in epithelium than in stroma. With finasteride concentrations greater than 5 nM, competitive inhibition of 5 alpha-reductase occurred both in epithelium and stroma. The mean inhibition constant Ki[nM +/- SEM] was 7 +/- 3 and 31 +/- 3 in epithelium and stroma, respectively. In the presence of finasteride concentrations < or = 5 nM, the epithelial 5 alpha-reductase seems to be inhibited in an uncompetitive manner, whereas such low finasteride concentrations cause either no inhibition (1-2 nM) or competitive inhibition (5 nM) in stroma. Our present study provides evidence that the inhibitory effect of finasteride on 5 alpha-reductase is much stronger in epithelium than in stroma. Therefore, it is conceivable that the global size-reduction of BPH under finasteride treatment is primarily due to the regression of BPH epithelium.

5-alpha Reductase Inhibitors↗
PubMed1994

Three-year safety and efficacy data on the use of finasteride in the treatment of benign prostatic hyperplasia.

OBJECTIVE: To assess the long-term safety and efficacy of finasteride in the treatment of symptomatic benign prostatic hyperplasia in patients treated with finasteride 5 mg for thirty-six months. METHODS: Two large multicenter studies were used. Patients were randomly assigned to treatment with finasteride, 1 or 5 mg, or placebo for twelve months. After completing twelve months of therapy, patients were invited to enter an open extension to the study in which all patients received finasteride 5 mg. Urinary symptoms, urinary flow rate, prostate volume, and serum concentrations of prostate-specific antigen and dihydrotestosterone were measured periodically during the study. RESULTS: After thirty-six months of treatment with finasteride 5 mg, prostate volume was reduced from baseline by approximately 27 percent, maximum urinary flow rate improved by approximately 2.3 mL/second, and symptom scores improved by 3.6 points. Forty-two percent of patients had a 30 percent or greater decrease in prostate volume, 40 percent of patients showed an increase of 3 mL/second or more in maximum urinary flow rate, and 48 percent of patients experienced a 50 percent or greater improvement in symptom scores. Finasteride was well tolerated and there was no evidence of increased adverse experiences with increased duration of treatment. CONCLUSIONS: The excellent safety profile and sustained clinical efficacy, over thirty-six months, of daily treatment with finasteride 5 mg recommend finasteride as a low-risk medical option for the treatment of symptomatic benign prostatic hyperplasia.

Adult↗
PubMed1995

Can finasteride reverse the progress of benign prostatic hyperplasia? A two-year placebo-controlled study. The Scandinavian BPH Study Group.

OBJECTIVES: To study if placebo-induced improvement in men with symptomatic benign prostatic hyperplasia (BPH) is maintained over 2 years, and to study the efficacy and safety from intervention with finasteride 5 mg for 24 months. METHODS: This was a multicenter, double-blind, placebo-controlled study involving 707 patients with moderate symptoms of BPH enrolled at 59 centers in five Scandinavian countries. Following enrollment and a 4-week single-blind placebo run-in period, patients were randomized to receive finasteride 5 mg once daily or placebo for 24 months. Urinary symptoms, urinary flow rate, prostate volume, postvoiding residual urinary volume, and serum concentrations of prostate-specific antigen together with laboratory safety parameters were measured at entry and at months 12 and 24. Interim physical and laboratory examinations were performed when indicated clinically. RESULTS: In finasteride-treated patients the total symptom score improved throughout the study, with a significant difference between the two groups at 24 months (P < or = 0.01), whereas in placebo-treated patients, there was an initial improvement in the symptom score but no change from baseline at 24 months. The maximum urinary flow rate decreased in the placebo group, but improved in the finasteride group, resulting in a between-group difference of 1.8 mL/s at 24 months (P < or = 0.01). The mean change in prostate volume was +12% in the placebo group versus -19% in the finasteride-treated group (P < 0.01). Finasteride was generally well tolerated throughout the 2-year study period. CONCLUSIONS: The efficacy of therapy with finasteride 5 mg in improving both symptoms and maximum urinary flow rate and reducing prostate volume has been shown to be maintained during 24 months while patients receiving placebo experienced a return to baseline or deterioration of these parameters during the study. These results demonstrate that finasteride can reverse the natural progression of BPH.

Aged↗
PubMedDate not supplied

Efficacy and tolerability of finasteride in symptomatic benign prostatic hyperplasia: a primary care study. Primary Care Investigator Study Group.

Because increasing numbers of men are seeking treatment for benign prostatic hyperplasia (BPH) from primary care physicians, we sought to assess the efficacy and tolerability of finasteride in a primary care setting. In this randomized, double-masked study, 2,112 men with symptomatic BPH received either finasteride (n = 1,589) or placebo (n = 523) for 1 year. At 3, 6, 9, and 12 months, urinary symptoms were measured using the American Urological Association Symptom Index (AUASI). Quality of life was assessed using the BPH Impact Index (BII), which assessed bother, worry, physical discomfort, and restriction in activities. Both patients and investigators assessed overall urologic status. Investigators assessed the effect of the drug on plasma lipids in a subset of patients. Patients treated with finasteride had a statistically significant mean decrease in AUASI scores compared with patients treated with placebo beginning at month 6 and continuing throughout the study. At month 12, adjusted mean decreases in AUASI scores were -4.96 for finasteride versus -3.71 for placebo. Statistically significant differences in favor of finasteride were also noted on BII at months 9 and 12. Patient and investigator overall assessments showed greater improvement in the finasteride group beginning at month 6. The incidence of drug-related sexual adverse experiences was significantly greater in finasteride-treated patients but led to withdrawal in only 2.2% of these patients. Overall lipid profile was not significantly altered in either group. Based on improvement in symptoms and quality of life, and on its favorable tolerability profile, finasteride should be considered by primary care physicians for management of symptomatic BPH.

Aged↗
PubMed1993

Effect of combination treatment with zanoterone (WIN 49596), a steroidal androgen receptor antagonist, and finasteride (MK-906), a steroidal 5 alpha-reductase inhibitor, on the prostate and testes of beagle dogs.

The effects of the steroidal androgen receptor antagonist zanoterone (WIN 49596) and the steroidal 5 alpha-reductase inhibitor finasteride (MK-906) either alone or in combination on prostatic size, histomorphology, and biochemistry were determined in the intact male dog. Additionally, the effects of treatment with zanoterone and/or finasteride on testicular size, serum testosterone and LH levels, and spermatogenesis were determined in the same dogs. Daily oral treatment for 16 weeks with either zanoterone alone at 10 mg/kg.day or finasteride alone at 1.0 mg/kg.day reduced (P < 0.05) the size of the prostate, resulted in mild to moderate diffuse glandular atrophy of the prostate, and decreased prostatic DNA and prostatic arginine esterase (the primary canine prostatic protein) levels compared to those in intact controls. These changes occurred with no effect on testicular weight, testicular histomorphology, daily sperm production, or serum LH levels. Serum testosterone concentrations were increased (P < 0.05) approximately 3-fold in the 10 mg/kg.day zanoterone treatment group compared to those in intact controls. Combination treatment of male dogs for 16 weeks with zanoterone (10 mg/kg.day) plus finasteride (1.0 mg/kg.day) orally also reduced (P < 0.05) prostate size, resulted in moderate to marked diffuse prostatic glandular atrophy, and decreased prostatic DNA and arginine esterase levels more than either drug alone, without affecting testicular size, testicular histomorphology, serum LH concentrations, or serum testosterone concentrations compared to those in intact controls. The effects of combination treatment with zanoterone and finasteride on prostatic size; histomorphology; and DNA, arginine esterase protein, and arginine esterase mRNA levels were similar to those observed in castrate controls. In addition, in situ estimates of prostatic size using transrectal ultrasonography indicated that the median time to 70% prostatic regression in dogs administered combination zanoterone plus finasteride was similar to that in castrate controls (9.6 and 9.3 weeks, respectively), indicating that the combination was more effective in causing prostatic regression than either drug alone. Finally, at the dosages used, no adverse effects of combination treatment with zanoterone plus finasteride on testicular or other major body organ weights were observed. Based on these results, combination therapy using zanoterone and finasteride for the treatment of human androgen-dependent disorders such as benign prostatic hyperplasia and prostate cancer has potential utility.

Androstenes↗
PubMed1995

Evidence for atrophy and apoptosis in the ventral prostate of rats given the 5 alpha-reductase inhibitor finasteride.

Castration causes cell loss in the rat ventral prostate through a process called apoptosis. Although 5 alpha-reductase inhibition also causes prostate cell loss, the mechanisms involved have been debated. To investigate this question further, we have evaluated the histological responses of the rat ventral prostate to both castration and 5 alpha-reductase inhibition. Rats were left intact, castrated, or given the selective 5 alpha-reductase inhibitor finasteride. After 4, 9, 14, and 21 days the prostates were excised, the androgen and DNA content determined, and the tissue was subjected to histological and histomorphometric analysis. Finasteride and castration decreased prostate weight at day 21 by 65% and 93%, respectively. Castration decreased DNA content (micrograms per prostate) by a maximum of 88% at 14 days. Finasteride had no significant effect on DNA content after 4 days and decreased DNA content by a maximum of 52% at 14 days. When castrate prostate sections were stained for tissue transglutaminase, a marker of apoptotic cell death, a maximum of 23% of epithelial cells were stained by day 14 with a return to control levels by day 21. Finasteride caused a less intense increase in staining in which 16% of epithelial cells stained for tissue transglutaminase on day 9 with a return to baseline by day 14. When prostate sections were stained for DNA breaks, another marker of cell death, castration, caused a peak of staining on day 4 with 6% of epithelial cells staining and a return to near control levels by day 21. Finasteride-induced staining was less intense with peak staining at day 4 (0.7% of epithelial cells) and a return to control values by day 9. Morphometrics were used to assess the effect of castration and finasteride on prostate duct size and epithelial cell mass. After 4 days of finasteride treatment, the mean ductal mass decreased by 47%, with no significant change thereafter. The mean epithelial cell mass decreased by 15% on day 4 and 60% on day 9, with no further decrease thereafter. Castration caused a more rapid and greater decrease in both morphometric parameters with a 95% reduction in the mass of prostate ducts and a 93% decrease in epithelial cell mass by day 9. We conclude that castration induces a more profound involution of the rat ventral prostate than does 5 alpha-reductase inhibition. Cell loss occurs in both groups, but the degree of cell loss is less with finasteride.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1996

Evidence for atrophy and apoptosis in the prostates of men given finasteride.

Finasteride, a 5 alpha-reductase inhibitor, decreases prostate size and improves symptoms in men with benign prostatic hyperplasia. However, little is known about prostate histopathology in men taking finasteride. To determine the mechanism by which finasteride reduces prostate size, tissue was collected at the time of prostatectomy from men taking either no medication (n = 10) or 5 mg finasteride daily for 6-18 days (n = 6; group 1), 23-73 days (n = 5; group 2), or 3 months to 4 yr (n = 5; group 3). To assess whether finasteride causes epithelial atrophy, morphometric measurement of epithelial cell and duct width was used. The mean epithelial cell width in control prostates (mean +/- SEM, 21 +/- 0.7 microns) decreased with duration of treatment to 19 +/- 1 microns in group 1, 15 +/- 2 microns in group 2, and 8 +/- 0.3 microns in group 3. Mean duct width decreased from 135 +/- 6 microns in the control prostates to 128 +/- 10 microns in group 1, 103 +/- 3 microns in group 2, and 63 +/- 6 microns in group 3. To assess whether prostate cell death was occurring, sections were in situ end labeled for DNA breaks and immunostained for tissue transglutaminase (tTG), a marker of apoptosis (programmed cell death). The percentage of epithelial cells staining for DNA breaks was 0.4 +/- 0.2 in control prostates, 2.8 +/- 0.9 in group 1, 1.7 +/- 0.5 in group 2, and 0.7 +/- 0.3 microns in group 3. Anti-tTG staining of epithelial cells was graded on a scale of 0-4. In control prostates, 3 +/- 1% of the ducts were grade 3 or 4 (> 50% of epithelial cells staining). In finasteride-treated prostates, 2 +/- 2% of the prostates in group 1, 13 +/- 4% of the prostates in group 2, and 0.5 +/- 0.5% of the prostates in group 3 were grade 3-4. These results indicate that a progressive decrease in epithelial cell size and function occurs during the first several months in the prostates of men treated with finasteride. The staining for DNA breaks and the tTG staining also indicate that an increased rate of apoptosis is occurring transiently in these prostates. We conclude that finasteride causes prostate involution through a combination of atrophy and cell death.

5-alpha Reductase Inhibitors↗
PubMed1994

Metabolism of finasteride in rat hepatic microsomes: age and sex differences and effects of P450 inducers.

1. The age- and sex-related metabolism of finasteride and the effects of P450 inducers and inhibitors were investigated using rat hepatic microsomes. 2. No marked age difference (3-13 weeks) in the rates of finasteride disappearance and the formation of 1 (omega-hydroxyfinasteride) and 4 (6 alpha-OH finasteride) was observed in the male rat. Whereas the rate of 1 formation remained about the same in male rat aged 1 year as compared with rat aged 7 weeks, a 21 and 45% decrease in the rate of finasteride disappearance and 4 formation, respectively, were observed. 3. The rates of finasteride disappearance and metabolite formation 1 and 4 in the female rat decreased with an increase in age (3-7 weeks). Metabolite 4 was hardly formed by the hepatic microsomes from the female rat at 7 weeks of age. 4. Hepatic microsomes from the male rat treated with phenobarbital (PB) and dexamethasone (Dex) increased the rate of the finasteride disappearance (PB, 5.5-fold; Dex, 11.6-fold), whereas no increase in this activity was observed after administration of beta-naphthoflavone (BNF). Similarly, pretreatment of the female rat with PB and Dex resulted in increases of 26.6 and 8.4-fold in the rate of finasteride disappearance, respectively, whereas no inductive effect on this activity was observed in the BNF-treated female rat. 5. These observations suggest that finasteride is metabolized by P4502B, P4502C, and P4503A subfamilies in the male rat and by P4502B and P4502C subfamilies in the female rat.

Aging↗
PubMedDate not supplied

Therapeutic effects of finasteride in benign prostatic hyperplasia: a randomized double-blind controlled trial.

The clinical effects of finasteride, a 5 alpha-reductase inhibitor, in patients with benign prostatic hyperplasia (BPH) were evaluated in a double-blind, placebo-controlled study. Forty-six patients with symptomatic BPH were randomly assigned to 2 groups, the finasteride group and the placebo group. The finasteride group received 5 mg of finasteride daily for 6 months. Prostate volume, urinary flow, urinary symptoms, serum prostate-specific antigen (PSA) and adverse events were determined before and after treatment. After 6 months of treatment the patients treated with 5 mg of finasteride per day had a 30% decrease in their total urinary symptom score, a 14% decrease in prostate volume and a 0.9 ng/dL decrease of PSA. Their maximal urinary flow rate increased by 1.42 mL per second and the mean urinary flow rate increased by 0.64 mL per second. The patients given placebo showed no significant changes in their prostate volume, serum PSA and maximal and mean urinary flow rate. However, the symptom scores in the placebo group also decreased significantly. When compared with the placebo group, those in the finasteride group had significantly lower prostate volume, serum PSA, maximal urinary flow rate and urinary symptoms, but not mean urinary flow rate. The frequency of adverse events was low in both the finasteride and placebo groups. These results show that finasteride may be an effective and safe alternative for the treatment of patients with BPH.

Aged↗
PubMed1997

[Treatment of benign prostatic hyperplasia with finasteride. Results after 7 years of follow-up].

Our centre took part in an international, multicentre, Phase III trial with Finasteride (MK-906) in the treatment of BPH. In the first year, this was a double-blind, randomised, placebo-controlled study which included 25 patients who were randomly assigned: 9 to treatment with placebo, 8 to finasteride 1 mg and 8 to finasteride 5 mg. After the first year, all patients were assigned to finasteride 5 mg as a single daily dose taken before breakfast. Of the 25 patients who started the trial, 7 have completed 7 years treatment (28%): 1 from the placebo group. 1 from finasteride 1 mg, and 5 who took finasteride 5 mg throughout the study. Total symptoms score, assessed by the modified Boyarsky questionnaire, improved during the first year 4.97 points (51%) and remained unchanged up to year 7 with a final reduction of 6.2 points (64%). Percentual increase in peak urinary flow during follow-up ranged between 21 and 45.9% with an absolute increase at 7 years of 4.2 mL/seg (47.5%) and a reduction in prostate volume of 26%. Finasteride tolerance was excellent at all times, and no serious clinical reaction was seen in laboratory parameters. Two patients reported decreased libido and sexual potency and 1 decreased libido. In summary, since after 7 years of treatment efficacy is maintained in at least 30% of patients with an excellent safety profile, finasteride can be considered an alternative in the medical treatment of BPH.

Double-Blind Method↗
PubMed1994

Leydig cell hyperplasia and adenomas in mice treated with finasteride, a 5 alpha-reductase inhibitor: a possible mechanism.

Finasteride is a selective inhibitor of the enzyme 5 alpha-reductase which is responsible for the conversion of testosterone (T) to dihydrotestosterone (DHT). Finasteride is indicated for the treatment of benign prostatic hyperplasia in man (approximately 0.1 mg/kg/day). The effect of long-term treatment was studied in mice given high doses (2.5, 25, and 250 mg/kg/day) of finasteride for 83 weeks. In finasteride-treated mice, increased incidences of testicular Leydig cell hyperplasia (52% compared to 24% in control group) at doses equal to or greater than 25 mg/kg/day and Leydig cell adenomas (32% compared to 0.5% in control group) at 250 mg/kg/day were observed. There were no drug-related effects on the seminiferous tubules. Since luteinizing hormone (LH) is a trophic hormone for Leydig cells, short-term studies (5 to 14 weeks) were done to investigate the relationship between Leydig cell hyperplasia and serum LH levels in finasteride-treated mice. In these studies, there was a positive correlation between the drug-related increased incidence of Leydig cell hyperplasia and a statistically significant (p < or = 0.05) increase in serum LH levels in finasteride-treated (250 mg/kg/day) mice. Furthermore, studies in castrated male mice showed that the suppression of serum LH levels by T is reversible by inhibition of conversion of T to DHT with finasteride (250 mg/kg/day), supporting the hypothesis that DHT is involved in the regulation of LH release in mice.(ABSTRACT TRUNCATED AT 250 WORDS)

5-alpha Reductase Inhibitors↗
PubMed1997

[Combination of Sabal and Urtica extract vs. finasteride in benign prostatic hyperplasia (Aiken stages I to II). Comparison of therapeutic effectiveness in a one year double-blind study].

Therapeutic equivalence should be demonstrated in a randomised, reference-controlled multicentric double blind clinical trial with PRO 160/120, a combination of Sabal- and Urtica-Extract, and Finasteride, respectively, in patients suffering from benign prostatic hyperplasia (BPH, Stage I to II according to Aiken). The study involved 543 patients, who were treated for 48 weeks with two capsules of PRO 160/120 or one capsule of Finasteride per day, in a double dummy design. Primary variable was the change of the maximum urinary flow after 24 weeks of therapy in comparison to therapy start. As secondary variables urodynamic parameters such as average urinary flow, miction volume and miction time were monitored. Urinary symptoms were recorded by the International-Prostate-Symptom-Score (I-PSS, Paris 1993). Additionally, the impacts of the symptoms on quality of life had been assessed by a quality of life questionnaire according to The American Urological Association Measurement Committee (1991). An increase of the urinary flow rate could be observed in both treatment groups (1.9 ml/s with PRO 160/ 120; 2.4 ml/s with Finasteride). During the trial, the average urinary flow increased, whereas the miction time decreased in both groups in a similar extent. The miction volume did not show any relevant differences after treatment with either PRO 160/120 or Finasteride. The I-PSS decreased from 11.3 at the therapy start to 8.2 after 24 weeks and 6.5 (week 48) under PRO 160/120 and from 11.8 to 8.0 and 6.2, under Finasteride, respectively. Accordingly, life quality improved between therapy start and therapy end from 7.5 to 4.3 with PRO 160/120 and from 7.7 to 4.1 with Finasteride. In terms of safety aspects less adverse events occurred with the Sabal/Urtica-Extract as with Finasteride. Especially less cases of diminished ejaculation volume, erectile dysfunction and headache have been reported.

Aged↗
PubMed1994

Qualitative and quantitative evaluation of prostatic histomorphology in rats following chronic treatment with finasteride, a 5-alpha reductase inhibitor.

OBJECTIVE: To determine any potential direct and/or indirect effects of elevated intraprostatic T levels on the prostates of rats chronically (1-2 years) exposed to high doses (160 mg/kg/day) of finasteride, a selective inhibitor of 5-alpha reductase. METHODS: Sprague-Dawley male rats were administered daily finasteride by oral gavage. Prostates from all rats were weighed, fixed in 10% neutral buffered formalin, and processed for light microscopic examination. The volume fractions of the prostatic glandular and stromal compartments were quantitated by morphometric analysis. RESULTS: Administration of finasteride at doses of 20, 40, and 80 mg/kg/day for one year resulted in a significant (P < or = 0.05) decrease in prostatic weight; prostatic atrophy was evident by light microscopy. Morphometric analysis of the prostate showed that chronic finasteride administration resulted in a significant (P < or = 0.001) decrease in the absolute volume of both glandular (-65.2%) and stromal (-57.1%) compartments of the prostate. Furthermore, the total number of epithelial and stromal cells per gland were significantly (P < or = 0.002) decreased in finasteride-treated rats compared with vehicle controls; the magnitude of mean decrease was 69.8 percent and 50.6 percent of controls in epithelial and stromal cells, respectively. In addition, prostates from all two hundred fifty rats in a two-year study were qualitatively evaluated by light microscopy. Administration of finasteride at doses ranging from 2.5 mg/kg/day to 160 mg/kg/day for two years did not result in an increase over the background incidence of prostatic focal hyperplasia or adenoma. No malignant tumors of the prostate were seen in any of the groups. CONCLUSIONS: These studies have demonstrated that the expected pharmacologic effects of finasteride on the prostate are maintained following chronic treatment and that there was no evidence of a direct and/or an indirect effect of elevated intraprostatic T on prostatic morphology in rats.

5-alpha Reductase Inhibitors↗
PubMedDate not supplied

Age-related changes in brain and pituitary 5 alpha-reductase with finasteride (Proscar) treatment.

Finasteride (Proscar), a 5 alpha-reductase inhibitor, was administered with or without 5 alpha-dihydrotestosterone (DHT) in juvenile (28), peripubertal (48), or young adult (68-day-old) male rats. Luteinizing hormone (LH) levels and ventral prostate (VP) weights monitored the efficacy of the treatments. For each postnatal day tested, LH hormone levels were not significantly altered by finasteride, suggesting that 5 alpha-reductase inhibition does not modulate LH in male rats using this protocol. Finasteride plus DHT treatment significantly decreased LH levels. Conversely, VP weights were significantly decreased in finasteride-treated animals while finasteride plus DHT treatment significantly increased VP values. Finasteride plus DHT treatment significantly decreased pituitary, but not brain, 5 alpha-reductase for each postnatal day tested. In finasteride-treated animals, hypothalamic and pituitary 5 alpha-reductase were significantly inhibited in young adult animals, whereas the activities were not altered in juvenile or peripubertal male rats. These data suggest that a different mechanism may regulate 5 alpha-reductase with the aging of the central nervous system and pituitary.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗