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Prospective randomized trial comparing flutamide as adjuvant treatment versus observation after radical prostatectomy for locally advanced, lymph node-negative prostate cancer.

OBJECTIVE: To assess the efficacy and the tolerability of flutamide as adjuvant treatment after radical prostatectomy for locally advanced, lymph node-negative prostate cancer. METHODS: Men with locally advanced, lymph node-negative prostate cancer were randomized after radical prostatectomy to receive either flutamide 750mg daily or no adjuvant treatment. Recurrence-free and overall survival were the study end points. Recurrence was defined as a PSA value greater than 5ng/ml or two values greater than 2ng/ml more than three months apart with increasing tendency or three values greater than 1ng/ml more than three months apart with increasing tendency or any clinical recurrence. RESULTS: 309 patients (157 in the control arm and 152 in the flutamide arm) were eligible for efficacy analysis. The median follow-up was 6.1 years. Recurrence-free survival was better in the flutamide group ( P=0.0041), there was, however, no detectable difference in overall survival ( p=0.92 ). Moreover, there was a considerable toxicity reported in the flutamide group. CONCLUSION: Although having some effect on disease recurrence, adjuvant flutamide treatment does not improve median-term overall survival after radical prostatectomy for locally advanced, lymph node-negative prostate cancer.

Aged↗

Involvement of serotoninergic mechanism in analgesia by castration and flutamide, a testosterone antagonist, in the rat formalin test.

Several studies have suggested that testosterone has a role in nociception. Recently, we have shown that castration and flutamide, a testosterone antagonist, induce analgesia in the late phase of formalin test, which is related to increase of 5-HT levels in the dorsal horn of the lumbar spinal cord. The aim of the present study was to investigate the effect of fluoxetine, a selective serotonin reuptake inhibitor, on castration and flutamide-induced analgesia in order to further explore the role of 5-HT systems in such analgesia. Four weeks after castration, there was an analgesia in the late phase of formalin test, and this was potentiated by acute (0.32 mg kg(-1) ip) treatment of fluoxetine. Furthermore, coadministration of fluoxetine (0.32 mg kg(-1) ip) and flutamide (10 mg kg(-1) ip) produced more antinociceptive effect than those animals receiving fluoxetine and flutamide alone. The analgesic effect of fluoxetine (0.32 mg kg(-1) ip) and flutamide (10 mg kg(-1) ip) was abolished by pretreatment with 5,7-DHT (100 microg/rat it) and naloxone (2 mg kg(-1) ip). In summary, our data suggest that fluoxetine and flutamide have antinociceptive effects in tonic inflammatory pain through functional alteration of serotonergic systems, and their effects are potentiated by coadministration. The possible role of opioidergic system in their antinociceptive effect cannot be neglected.

Analgesia↗

Comparison of flutamide and spironolactone in the treatment of hirsutism: a randomized controlled trial.

OBJECTIVE: To compare the clinical efficacy and safety of the pure antiandrogen flutamide and the steroidal derivative spironolactone in the treatment of hirsutism in women. DESIGN: Fifty-three premenopausal women suffering from moderate to severe hirsutism were randomized into two groups and received either flutamide or spironolactone in association with a triphasic oral contraceptive (OC) pill. Hirsutism, acne, seborrhea, alopecia, and side effects were monitored monthly for a treatment period of 9 months and a follow-up after treatment period of 6 months. Blood samples were taken at each visit for assessment of endocrine, biochemical, and hematologic parameters. RESULTS: After only 6 months of therapy, flutamide caused a maximal reduction in the hirsutism score to a value within almost normal range; during the same period, spironolactone caused only a 30% reduction of the hirsutism score. Whereas flutamide caused a dramatic (80%) decrease in total acne, seborrhea, and hair loss score after only 3 months of therapy, spironolactone caused only a 50% reduction in acne and seborrhea, with no significant effect on the hair loss score. Four patients in the spironolactone group but only one in the flutamide group stopped the medication because of adverse side effects. CONCLUSION: The present data obtained in a randomized prospective study clearly demonstrate that the pure antiandrogen flutamide is superior to spironolactone in the treatment of female hirsutism and its related androgen-dependent symptoms and signs in women.

Adult↗

Flutamide in the treatment of hirsutism: long-term clinical effects, endocrine changes, and androgen receptor behavior.

OBJECTIVE: To investigate the long-term effects of treatment with low doses of flutamide on clinical and hormonal parameters, as well as on the androgen receptor status, in hirsute women. DESIGN: Eighteen hirsute patients with regular menses were studied basally and during treatment with 125 mg flutamide, three times per day for 12 months. Barrier or intrauterine contraception was used during the study in sexually active women. Safety parameters were assessed throughout the study. Hirsutism, graded by the modified Ferriman-Gallwey score, and hormonal parameters were evaluated basally and at 4-month intervals during treatment. Gonadotropin-releasing hormone and ACTH stimulation tests were performed before and after 3 to 4 months of therapy. In addition, the concentration of androgen receptors in mononuclear leukocytes was measured, in both the follicular and luteal phases of the menstrual cycle, basally and after 4 months of flutamide treatment. RESULTS: Flutamide was well tolerated in all women, with the noticeable exception of one patient who presented increased serum transaminase after 8 months of therapy. Hirsutism markedly improved in all women during the treatment (Ferriman-Gallwey score after 1 year: 4.1 +/- 0.5 versus 14.1 +/- 0.9). A reduction of serum androgens was found, whereas no change was observed in either basal or GnRH-stimulated gonadotropins or in the cortisol and 17 alpha-hydroxyprogesterone response to ACTH. Cycles remained ovulatory. Before treatment, the number of androgen receptors was higher in the luteal than in the follicular phase. This rhythmic differentiation disappeared after the patients had been given the antiandrogen drug. CONCLUSIONS: Flutamide is effective in the treatment of hirsutism but requires constant surveillance of liver function. Androgen receptor blockade might be potentiated by a reduction of serum androgens. Flutamide affects androgen receptor behavior during the menstrual cycle. The meaning of this finding remains to be elucidated.

Acne Vulgaris↗

The efficacy of 250 mg/day flutamide in the treatment of patients with hirsutism.

OBJECTIVE: To investigate the effects of low dose flutamide (250 mg/d) on hirsutism score and hormone levels in women with hirsutism. DESIGN: Nonrandomized, prospective clinical trial. PATIENTS: Forty-one patients with moderate-severe hirsutism were included in the study. INTERVENTION: Hirsute patients received 250 mg/d flutamide for a period of 6 months. MAIN OUTCOME MEASURES: Hirsutism score, FSH, LH, E2, total T, free T, androstenedione, DHEAS, PRL, 17-hydroxyprogesterone, and sex hormone-binding globulin levels were detected in all the patients before treatment and every 3 months during treatment. RESULTS: Treatment with the antiandrogen flutamide resulted in a particularly rapid and marked decrease in the hirsutism score, which decreased from 17.48 +/- 5.35 to 5.07 +/- 2.89 after 6 months. No significant changes in the levels of hormone and no serious side effects were observed in the study. CONCLUSION: The low-dose flutamide, 250 mg/d, is a cost-effective drug in the treatment of hirsutism. Low-dose flutamide may be used in place of high-dose flutamide, 500 to 750 mg/d.

Adolescent↗

A comparison between two doses of flutamide (250 mg/d and 500 mg/d) in the treatment of hirsutism.

OBJECTIVE: To compare the effects of flutamide at 250 mg/d and 500 mg/d in the treatment of hirsutism. DESIGN: Randomized, prospective clinical study. PATIENT(S): Sixty-five patients with moderate to severe hirsutism. INTERVENTION(S): Group I (n = 35) patients were treated with flutamide, 250 mg/d, and group II (n = 30) patients were treated with flutamide, 500 mg/d, for 12 months. Baseline hormone levels, body mass index, and hirsutism scores were similar between the groups. Hirsutism score, hormone levels, and multiscreen blood chemistry were measured at 3-month intervals for 12 months. RESULT(S): The modified Ferriman-Gallwey scores for hirsutism decreased significantly at months 6 and 12 from a mean +/- SEM of 17.8 +/- 0.9 to 6.0 +/- 0.6 (P < 0.001) and 17.8 +/- 0.9 to 4.8 +/- 0.7 (P < 0.001) in group I and from 17.0 +/- 0.9 to 6.6 +/- 0.7 and 17.0 +/- 0.9 to 5.2 +/- 0.7 (P < 0.001) in group II, respectively. The reductions in hirsutism scores (mean +/- SEM) were similar in group I at 6 months (64.6% +/- 2.5%) and at 12 months (71.2% +/- 2.2%) and in group II at 6 months (62.1% +/- 3.0%) and at 12 months (70.3% +/- 3.0%). The percent reductions in hirsutiam scores at 6 and at 12 months were similar within group I (64.6% +/- 2.5% and 71.2% +/- 2.2%) and group II (62.1% +/- 3.0% and 70.3% +/- 3.0%), respectively. The decreases in hirsutism scores in the first 6 months were more significant than in the last 6 months of treatment in both groups. There were no significant differences in any of the hormone levels during therapy in either group. One patient in group II was excluded from the study because of liver dysfunction. CONCLUSION(S): This study shows that two different doses of flutamide (250 mg/d and 500 mg/d) are similarly effective in reducing hair growth. Flutamide at a dose of either 250 mg/d or 500 mg/d has no further effect after 6 months. We conclude that if flutamide is administered at a dose of 250 mg/d it may represent an effective and well tolerated treatment with reduced cost for the patient.

Adult↗

Comparison of finasteride and flutamide in the treatment of idiopathic hirsutism.

OBJECTIVE: To compare the effectiveness of finasteride and flutamide in the treatment of idiopathic hirsutism. DESIGN: Randomized study. SETTING: Department of Gynecological Endocrinology, University of Brescia, Italy. PATIENT(S): Forty-six women with idiopathic hirsutism were selected. INTERVENTION(S): Patients were assigned randomly to receive 5 mg of finasteride once daily or 250 mg of flutamide twice daily for 12 consecutive months. MAIN OUTCOME MEASURE(S): Hirsutism was evaluated at 6 and 12 months of therapy by measuring the Ferriman-Gallwey score and the terminal-hair diameters (microm) taken from different body areas. Blood samples were taken and side effects were monitored during the treatment. RESULT(S): Both finasteride and flutamide induced a statistically significant decrease in hirsutism scores and hair diameters at the end of 12 months. Finasteride reduced the Ferriman-Gallwey score by 20.5% at 6 months and by 34.2% at 12 months, and hair diameter by 18.9%-23.6% at 6 months and by 29.6%-37.9% at 12 months. Flutamide reduced the Ferriman-Gallwey score by 26.6% at 6 months and by 50.9% at 12 months, and hair diameter by 22.3%-28.2% at 6 months and by 47.7%-56.5% at 12 months. Flutamide did not induce hormonal variations, whereas finasteride increased T levels by 60% and decreased 3alpha-androstanediol glucuronide by 69.5% at 12 months. CONCLUSION(S): Both drugs were effective in the treatment of idiopathic hirsutism, but flutamide was more effective than finasteride.

Adolescent↗

Finasteride and flutamide therapy in patients with advanced prostate cancer: response to subsequent castration and long-term follow-up.

OBJECTIVES: To report the efficacy of castration after progression on finasteride and flutamide. Standard androgen deprivation strategies for prostate cancer typically lead to castrate levels of testosterone. One alternative is the use of finasteride and flutamide. METHODS: A Phase II trial evaluated the combination of finasteride (5 mg/day) and flutamide (250 mg three times daily) in patients with rising prostate-specific antigen levels after local treatment for prostate cancer or with newly discovered metastatic disease. Patients were followed up for subsequent events, including castration-free, androgen-independent prostate cancer (AIPC)-free, and overall survival. RESULTS: With a median follow-up of 88 months, 5 patients (25%) continued on finasteride and flutamide, and 12 had stopped this combination and subsequently underwent medical or surgical castration. No patients experienced a flutamide withdrawal effect. All patients experienced more than a 50% decline in prostate-specific antigen after castration (mean 89%). The median protocol treatment failure-free survival was 29.9 months, the median castration-free survival was 37 months, and the median AIPC-free survival was 48.6 months. At 5 years, the overall survival rate was 65% (95% confidence interval 47% to 90%); 29% were alive and have not required castration, and 35% were alive and free of AIPC. CONCLUSIONS: Finasteride and flutamide have a durable effect in suppressing prostate-specific antigen progression in some men with advanced prostate cancer. Furthermore, castration induces secondary responses that may be of shorter duration than if started initially, although the overall period of hormonally responsive prostate cancer is more than 4 years.

Adenocarcinoma↗

Comparison of in vitro effects of the pure antiandrogens OH-flutamide, Casodex, and nilutamide on androgen-sensitive parameters.

OBJECTIVES: A combination of flutamide (Eulexin) or nilutamide (Anandron) with a luteinizing hormone-releasing hormone (LHRH) agonist or orchiectomy is the only therapy demonstrated to prolong life in prostate cancer. Recently, the low 50-mg daily dose of Casodex, an analogue of the pure antiandrogen flutamide, was chosen for clinical studies on the basis that the compound was 5 to 10 times more potent than flutamide, as suggested by data obtained in the inappropriate intact rat model. The present study was designed to compare the in vitro antiandrogenic activity of OH-flutamide (OH-FLU), the active metabolite of flutamide, Casodex, and nilutamide. METHODS: The effect of the antiandrogens was tested on two androgen-sensitive parameters, namely proliferation of the SEM-107 clone of Shionogi mouse mammary tumor cells and secretion of the GCDFP-15 (gross cystic disease fluid protein 15 kDa) in T-47D and ZR-75-1 human breast cancer cells. RESULTS: The twofold stimulation of Shionogi cell proliferation caused by a 10-day exposure to 1 nM testosterone was competitively reversed by incubation with OH-FLU, Casodex, or nilutamide, at the respective IC50 values of 72, 243, and 412 nM. Moreover, the marked increase in GCDFP-15 release induced by 1 nM testosterone was blocked by OH-FLU. Casodex, or nilutamide at respective IC50 values of 29, 180, and 87 nM in T-47D cells and at 35, 142, and 75 nM in ZR-75-1 cells. Similar data were detected in 4-androstenedione-induced Shionogi cell proliferation and in dihydrotestosterone-induced GCDFP-15 secretion in T-47D cells. CONCLUSIONS: OH-FLU is 3.1- to 7.8-fold more potent than Casodex, as measured on two in vitro androgen-sensitive parameters, in agreement with our recent in vivo data obtained in the model of castrated rats supplemented with 4-androstenedione implants, in which threefold greater potency of flutamide was observed. The present data, as well as other data from the literature, strongly indicate the need to choose a more appropriate dose of Casodex for the treatment of prostate cancer.

Androgen Antagonists↗

Effect of flutamide-induced androgen-receptor blockade on adenylate cyclase activation through G-protein coupled receptors in rat prostate.

The effect of the antiandrogen flutamide on the prostatic vasoactive intestinal peptide (VIP) receptor/effector system was studied in rats. Rats were s.c. injected with a daily dose of flutamide (15 mg/kg B.W.) or vehicle for 14 days. Drug treatment resulted in histological evidence of gland involution and increased plasma membrane fluidity as estimated by fluorescence spectroscopy. The number of VIP receptors and the stimulatory effect of VIP on adenylate cyclase activity in prostatic membranes decreased in flutamide-treated rats. However, the pattern of forskolin stimulation of the enzyme activity was not modified by this drug. Androgen-receptor blockade by flutamide also decreased the prostatic levels of alpha(s,) alpha(i1/2), and alpha(i3/0) G-protein subunits, as estimated by an immunological procedure. Whereas apoptotic DNA fragmentation was evidenced in prostate from 3-day castrated animals, a heterogeneous electrophoretic pattern was observed after flutamide treatment. Thus, androgen-receptor blockade by flutamide results in an important impairment of the components of the VIP receptor/effector system in rat prostate as well as in a modification of their coupling extent, which is presumably due to differences observed in plasma membrane fluidity. These results represent a crosstalk in the prostate between two mechanisms of signal transduction involved in cell proliferation.

Adenylyl Cyclases↗

Evaluation of flutamide genotoxicity in rats and in primary human hepatocytes.

Flutamide, an effective competitive inhibitor of the androgen receptor used orally for palliative treatment of prostatic carcinoma and regulation of prostatic hyperplasia was evaluated for its genotoxic effects in the intact rat and in primary cultures of human hepatocytes. Negative responses were obtained in all the in vivo assays as well as in the in vitro assay. In rats given a single oral dose of 500 mg/kg flutamide, fragmentation and repair of liver DNA were absent, and no increase was observed in the frequency of micronucleated hepatocytes. In the liver of rats given flutamide as initiating agent at the dose of 500 mg/kg/week for 6 successive weeks, gamma-glutamyltraspeptidase-positive foci were detected only in 3 of 10 rats. There was no evidence of a promoting effect on the development of aberrant crypt foci in rats given 100 mg/kg flutamide on alternate days for 8 successive weeks. In primary cultures of human hepatocytes from one male and one female donor DNA fragmentation as measured by the Comet assays, and DNA repair synthesis as revealed by quantitative autoradiography, were absent after a 20 hr exposure to flutamide concentrations ranging from 18 to 56 microM. Taken as a whole, our results seem to indicate that flutamide is a non-genotoxic drug.

Androgen Antagonists↗

Neoadjuvant flutamide monotherapy for locally confined prostate cancer.

BACKGROUND: We compared the clinical effects and impact on quality of life (QOL) of patients who received a 3-month course of flutamide monotherapy before radical prostatectomy with those who received a 3-month course of luteinizing hormone-releasing hormone (LHRH) agonist monotherapy. METHODS: Thirty-seven patients with non-metastatic prostate cancer were enrolled in this study (19, flutamide; 18, LHRH agonist). The rates of change of serum prostate-specific antigen (PSA) and testosterone levels, downsizing of prostate volume, the rate of organ confined disease, adverse effects and perioperative scores measured using the European Organization for Research and Treatment of Cancer Prostate Cancer Quality of Life Questionnaire (EORTC-P) and the Sapporo Medical University Sexual Function Questionnaire (SMUF) were analyzed. RESULTS: At radical prostatectomy, pathological variables were not significantly different in the two groups. Serum testosterone level was significantly higher (mean 359.2 compared to 10.5, P < 0.001), complete response rate of PSA (13% compared to 57%, P = 0.028) and rate of downsizing of prostate volume (mean, -17.7% compared to -35.4%, P = 0.038) were significantly lower in the flutamide group than in the LHRH group. After neoadjuvant hormone therapy, the scores on the sexual problem domain of EORTC-P (P = 0.033) and sexual desire score of SMUF (P = 0.021) were significantly higher in the flutamide group than in the LHRH group. At a median follow-up of 34 months after prostatectomy, biochemical failure-free survival rate in the flutamide group did not differ from that in the LHRH group. CONCLUSION: This study suggests that flutamide monotherapy can be an acceptable modality as an option for neoadjuvant hormone therapy.

Aged↗

Clinical utility of ursodeoxycholic acid in preventing flutamide-induced hepatopathy in patients with prostate cancer: a preliminary study.

BACKGROUND: The present study was designed to ascertain retrospectively the validity of ursodeoxycholic acid (UDCA) in the treatment of prostate cancer in terms of prophylactic effects on the occurrence of flutamide-induced hepatopathy in a large number of patients surveyed in a multi-center cooperative study. METHODS: One hundred and eighty-one patients (74.1 +/- 4.9 years) with prostate cancer treated with flutamide with (n = 70) or without (n = 111) UDCA were retrospectively evaluated and the occurrence of hepatopathy was compared between these two patient groups. RESULTS: Between patients treated with UDCA and those without it, no significant differences were noted in age, clinical stage, grade, duration of flutamide administration and serum prostate-specific antigen (PSA) levels before treatment. However, there were significant differences in the presence or absence of previous treatments and treatments used together with flutamide. The incidence of hepatopathy was 11.4% (8/70) in patients with UDCA and 32.4% (36/111) in those without it, showing a statistically significant difference (P < 0.05). The hepatopathy-free rate obtained by the Kaplan-Meier method was also significantly higher in patients with UDCA (88.4% 1 year following flutamide administration) than that in those without it (59.6%) (P < 0.005). CONCLUSION: These results suggest that UDCA has a prophylactic effect against flutamide-induced hepatopathy in patients with prostate cancer.

Aged↗

Effects of flutamide on puberty in male rats: an evaluation of the protocol for the assessment of pubertal development and thyroid function.

To establish a test protocol for the rodent 20-d thyroid/pubertal assay, flutamide, a non-steroidal androgen antagonist, was administered to intact male Sprague-Dawley rats from postnatal d 33 for 20 d, and several reproductive endpoints were examined to assess the sensitivity of a number of parameters with respect to the detection of endocrine-related effects. Immature male rats were divided into 4 groups and given flutamide once daily by oral gavage at doses of 0, 1, 5, or 25 mg/kg/d. Prepuce separation was significantly delayed in flutamide-treated rats (5 and 25 mg/kg/d). One day after the last dose, the rats were sacrificed. Flutamide treatment resulted in a significant reduction in the weights of epididymides, ventral prostate, seminal vesicles plus coagulating glands and fluid, levator ani plus bulbocavernosus muscles, Cowper's glands, and glans penis. The weight of adrenal glands decreased at 25 mg/kg/d, while testes and any other organ weights were unaffected. No microscopic changes were observed in the thyroid glands. Serum levels of testosterone were significantly increased in the flutamide-treated groups (5 and 25 mg/ kg/d) and serum levels of estradiol were also increased (25 mg/kg/d). No differences were observed in the serum thyroxine levels. These results indicate that flutamide delays puberty in the male rat, and its mode of action appears to be via altered secretion of steroids, which subsequently affect the development of the reproductive tract. Thus, this assay might be used as an alternative for screening antiandrogenic activities of chemicals.

Androgen Antagonists↗

The effect of flutamide on pulsatile gonadotrophin secretion in hyperandrogenaemic women.

The pulsatile gonadotrophin secretion in hyperandrogenaemic women was examined, following short-term androgen antagonism induced by flutamide, a specific androgen receptor blocker. Flutamide was administered to seven hyperandrogenaemic women and five normal cycling women, at a dose of 250 mg on the evening of day 1, followed by daily doses of 750 mg for 6 days. Blood samples were collected at 10 min intervals for 8 h before (day 1) and during treatment (days 2 and 6). Gonadotrophin and prolactin concentrations were measured in all samples while sex hormone concentrations were analysed in selected samples. Flutamide administration to hyperandrogenaemic women was followed by a decrease in luteinizing hormone (LH) pulse amplitude (P < 0.05), associated with an apparent decline in mean LH concentrations. Follicle stimulating hormone (FSH) showed a significant fall after 6 days of treatment (P < 0.05). Total testosterone, free testosterone, androstenedione and dihydroepiandrosterone sulphate were significantly decreased during flutamide administration, while sex-hormone-binding globulin and oestradiol were not affected. Normal women showed no significant changes in the above mentioned parameters. These results demonstrate that short-term androgen receptor blockade with flutamide reduces gonadotrophin secretion and androgen concentration in hyperandrogenaemic women. Since flutamide is devoid of intrinsic hormonal activity, it is suggested that the observed hormonal changes are secondary to the androgen blockade.

Adolescent↗

Comparative evaluation of a 5-day Hershberger assay utilizing mature male rats and a pubertal male assay for detection of flutamide's antiandrogenic activity.

A 5-day Hershberger assay utilizing mature male rats and a pubertal male assay were evaluated for the ability to detect antiandrogenic compounds such as flutamide, an androgen receptor antagonist. Six days after the operation, implantation with two silicon capsules containing testosterone (T) (30 mg/capsule) in castrated rats provided the ventral prostate and seminal vesicle weights as well as serum T and luteinizing hormone (LH) levels equivalent to those of the controls (non-castrated, non-implanted rats). Castrated rats implanted with two T-capsules (6 rats/dose) were treated by gavage for 5 days with vehicle (0.5% carboxymethylcellulose) or flutamide (0.15, 0.6, 2.5, or 10 mg/kg/day). Flutamide produced significant decreases in weights of the seminal vesicles and the levator ani plus bulbocavernosus muscles (> or =0.6 mg/kg/day) and ventral prostate (> or =2.5 mg/kg/day), and an increase in serum LH levels (> or =2.5 mg/kg/day), but no changes in serum T levels. When age-matched intact male rats were treated with 10-mg/kg/day flutamide, a significant increase in serum T levels was observed concomitant with a tendency of increased LH. The organ weights were also decreased; however, the changes were less than those in the castrated, T-implanted rats. Immature intact male rats (10 rats/dose) were treated for 20 days with flutamide (0, 0.15, 0.6, 2.5, or 10 mg/kg/day). Flutamide produced significant decreases in weights of the seminal vesicles, ventral prostate, and levator ani plus bulbocavernosus muscles at 2.5 and 10 mg/kg/day. Serum LH levels, but not T levels, were increased at 10 mg/kg/day. Statistical significance of some of these changes was not observed in the 6 animals/dose examined. Our findings support that the Hershberger assay, in the current conditions, is the most sensitive among the assays examined and a useful short-term screening method for the detection of antiandrogenic compounds.

Androgen Antagonists↗

Lack of feminization of the cremaster nucleus by prenatal flutamide administration in the rat and pig.

PURPOSE: The sexually dimorphic cremaster nucleus contains motoneurons that project via the genitofemoral nerve and theoretically direct androgen dependent testicular descent. The effects of flutamide on descent and masculinization of the cremaster nucleus were studied in the rat and pig. MATERIALS AND METHODS: Flutamide was given to pregnant rats and pigs on days 16 to 22 and 65 to 113 of gestation, respectively. Tissues were perfused and examined at birth (pigs) or at age 30 days (rats). Spinal cords were removed, sectioned and immunohistochemically stained for serotonin (rats) or substance P (pigs) to demarcate the position of the cremaster nucleus and allow the determination of cremaster motoneuron number. RESULTS: After exposure to flutamide testes were undescended in 6 of 9 rats and 7 of 10 pigs. Cremaster motoneuron number per nucleus were 288 +/- 22 in control versus 250 +/- 27 in flutamide treated rats, and 165 +/- 28 in control versus 148 +/- 24 in flutamide treated pigs. The decrease in motoneuron number by flutamide was significant in both species (p < 0.02) but it did not approach the levels in female rats (93 +/- 11) and pigs (57 +/- 12). Cremaster motoneuron number did not correlate with testicular position. Porcine undescended testes were associated with a significant increase in mean gubernacular volume. CONCLUSIONS: Unlike other sexually dimorphic spinal cord nuclei masculinization of the cremaster nucleus appears to be largely androgen independent and it does not correlate with ipsilateral testicular descent. These data suggest that androgens do not mediate descent of the testes via the efferent limb of the genitofemoral nerve.

Androgen Antagonists↗

Flutamide in men with prostatic intraepithelial neoplasia: a randomized, placebo-controlled chemoprevention trial.

High-grade prostatic intraepithelial neoplasia (HGPIN) has been identified as a premalignant change in the prostate that indicates increased risk of the subsequent development of prostate adenocarcinoma. Prior studies have suggested that androgen deprivation therapy causes a regression of HGPIN. We therefore conducted a chemoprevention trial assessing the efficacy of flutamide in reducing the rate of prostate adenocarcinoma development in men with HGPIN. Men with biopsyproven HGPIN but no evidence of prostate adenocarcinoma were randomized in a double-blind manner to either flutamide 250 mg/d or a placebo. Treatment was continued for 1 year. Repeat biopsies were obtained at 12 and 24 months. Quality of life and toxicities related to treatment were also measured. Sixty patients were randomized and began therapy with either flutamide or placebo. At 1 year, 14% of men receiving flutamide and 10% of men receiving placebo had developed prostate adenocarcinoma. Flutamide-associated toxicities were mild to moderate in severity. Quality-of-life measures did not show any differences between the 2 groups. This study showed no evidence of benefit from flutamide as a chemoprevention agent in men with HGPIN.

Aged↗