Influence of demographic factors and biochemical characteristics on the prostate-specific antigen (PSA) response to testosterone replacement therapy.

A retrospective study was performed to evaluate how the prostate-specific antigen (PSA) response to testosterone replacement therapy (TRT) varies with age, mode of testosterone treatment, and baseline levels of PSA and testosterone. In total, 48 consecutive hypogonadal men who completed 1 year of TRT were evaluated. All men had a negative prostate biopsy obtained prior to initiating TRT. Men received TRT in the form of intramuscular injections (n = 33) or topical gel (n = 25) based on clinical response. Comparisons in the change in PSA after 1 year of TRT were made based on various thresholds for age and baseline values of PSA, total testosterone (TT), and free testosterone (FT). Baseline levels of TT (297.7+/-156.6 vs 292.7+/-89.7 ng/dl; P = 0.88) and FT (0.95+/-0.3 vs 1.1+/-0.3 ng/dl; P = 0.08) were similar for the injection and transdermal groups, and both groups also had similar baseline PSA values (1.92+/-1.9 vs 1.71+/-1.9 ng/ml, respectively; P = 0.67). After 1 year of TRT, mean PSA values did not differ significantly between groups, nor did the mean increase in PSA (P > 0.05). The overall mean increase in PSA was 0.31+/-0.76 ng/ml. After one year of TRT, PSA was decreased in 21%, unchanged in 22%, and increased in 57%. Only 24% of the entire group demonstrated a PSA increase of 0.5 ng/ml or greater. No statistical difference was found in the change in PSA based on patient age, baseline PSA levels, or baseline levels of TT or FT. TRT causes only a mild increase in PSA in most hypogonadal men, and does not appear to be influenced by the mode of TRT, age, or baseline levels of PSA or testosterone.

Treatment of testosterone-induced gynecomastia with the aromatase inhibitor, anastrozole.

Gynecomastia is an unusual side effect associated with testosterone replacement therapy (TRT) that has been traditionally treated with surgery, radiation, or discontinuation of testosterone supplementation. We report here our experience with two cases of gynecomastia in men undergoing TRT who were successfully treated with the aromatase inhibitor anastrozole.

The use of the simplified International Index of Erectile Function (IIEF-5) as a diagnostic tool to study the prevalence of erectile dysfunction.

The purpose of this research was to determine the prevalence of erectile dysfunction (ED) in a non-selected population using the abridged 5-item version of the International Index of Erectile Function (IIEF-5) as a diagnostic tool. In a non-institutionalized population and during a free screening program for prostate cancer (Prostate Cancer Awareness Week of Santa Casa Hospital, Porto Alegre, Brazil), from 26 to 30 July 1998, all men who were attending were invited to complete a sexual activity questionnaire (the abridged 5-item version of the International Index of Erectile Function-IIEF-5) as a diagnostic tool for ED. The possible scores for the IIEF-5 range from 5 to 25, and ED was classified into five categories based on the scores: severe (5-7), moderate (8-11), mild to moderate (12-16), mild (17-21), and no ED (22-25). Of the 1071 men who participated in the program, 965 (90.1%) were included in this study. Of the responding men 850 were Caucasian (88%) and 115 were black (12%). The mean age of the men was 60.7 y, ranging from 40 to 90 y old. In this sample the prevalence of all degrees of ED was estimated as 53.9%. In this group of men, the degree of ED was mild in 21.5%, mild to moderate in 14.1%, moderate in 6.3%, and severe in 11.9%. According to age the rates of ED were: 40-49 (36.4%); 50-59 (42.5%); 60-69 (58.1%); 70-79 (79.4%), and over 80 y (100%) showed ED (P<0.05). The Pearson coefficients between the variables age and IIEF-5 showed a statistically significant inverse (negative) relation (r=-0.3449; P<0.05). ED is highly prevalent in men over 40 and this condition showed a clear relationship to aging, as demonstrated in other studies published. The simplified IIEF-5, as a diagnostic tool, showed to be an easy method, which can be used to evaluate this condition in studies with a great number of men.

Is there any relation between serum levels of total testosterone and the severity of erectile dysfunction?

The objective of this study was to correlate the severity of erectile dysfunction (ED) with the total testosterone serum levels (TT) in a normal population. During a screening program for the early diagnosis of prostate cancer, 1071 men aged from 40 to 90 y, were invited to answer the questionnaire of the Simplified International Index of Erectile Function (IIEF-5) as a method to diagnose and classify ED. The IIEF-5 scores ranged from 1 to 25 and the ED was classified into five groups according to the scores: severe (1-7), moderate (8-11), mild-moderate (12-16), mild (17-21) and no ED (22-25). Besides the questionnaire, all subjects had their TT serum levels determined based on the blood sample obtained between 08:00 and 10:00. The analysis of the relationship between the different degrees of ED and TT levels was then studied. Of the 1071 men, 965 were included in the study (90.1%). Eighty-eight percent of these were Caucasian and 12% black. The mean age of the population was 60.7 y. The prevalence of all degrees of ED was 53.9%. The degree of ED was mild in 21.5%, mild to moderate in 14.3%, moderate in 6.3% and severe in 11.9%. The variation of TT serum concentrations was similar (P>0.05) in the different age groups. Furthermore, the TT serum levels were not different for individuals with and without ED (P>0.05) and similar concentrations of TT was observed in the different severity degrees of ED (P>0.05). Only one (0.7%) man in the group of individual with maximal score had subnormal levels of TT. ED presented a clear association with the subjects' aging, but neither correlation between TT levels and ED, nor with its severity, could be demonstrated in the present study.

Effects of the chronic use of finasteride on testicular weight and spermatogenesis in Wistar rats.

OBJECTIVE: To evaluate spermatogenesis in rats chronically exposed to finasteride, as the recent use of finasteride in young men to prevent hair loss has raised concerns about chronic use and fertility. MATERIALS AND METHODS: Male Wistar rats (4 months old) were selected and divided into two groups. Group 1 (17 rats) received a finasteride suspension of 2 mg/kg/day in saline solution, 5 days/week for 10 months; group 2 (eight rats of the same age) were treated with placebo for the same period. At the end of the exposure the testes were weighed and processed for histological analysis. Spermatogenesis was evaluated as the mean number of seminiferous tubules with and without spermatozoids in their lumen, in five random fields on the same slide. Student's t-test was used to assess differences in the groups. RESULTS: In group 1, the mean (sd) weight of the testes was 1.55 (0.29) g and in group 2 1.58 (0.34) g (P>0.05). The histological analysis showed a mean of 13.35 (1.66) seminiferous tubules per field and 1.20 (3.30) tubules with no spermatozoids in group 1; in group 2 the respective values were 13.53 (1.46) and 0.06 (0.14) (P>0.05). CONCLUSION: Finasteride had no detectable effects on the quantitative and qualitative analysis of spermatogenesis in rats.

Beneficial effect of alpha-tocopherol in renal ischemia-reperfusion in rats.

We evaluated the effects of alpha-tocopherol (vitamin E) on the products of lipid peroxidation and serum creatinine levels in a rat model of renal ischemia-reperfusion. The animals were submitted to sham operation or renal ischemia-reperfusion, and they were pretreated with alpha-tocopherol or the vehicle saline. In four groups, we analyzed the lipid peroxidation products by measuring malondialdehyde and chemiluminescence levels. In the other three groups, we studied the serum creatinine levels after the procedures. In our study, the pretreatment with alpha-tocopherol reduced significantly the lipid peroxidation of renal cells and renal dysfunction induced by renal ischemia-reperfusion in rats.

Endoscopic treatment of choledocholithiasis in the era of laparoscopic cholecystectomy: prospective analysis of 386 patients.

BACKGROUND/AIMS: Endoscopic papillotomy is a well-established procedure for treating choledocholithiasis. The aim of this study is to expose our experience with this method in a prospectively collected series of 386 patients and to analyze the safety and efficacy of the pre-cut procedure. METHODOLOGY: Between October 1995 and December 1999, 760 endoscopic retrograde cholangiopancreatographies were performed in 670 patients. Of these, 449 were done to treat 386 patients with choledocholithiasis. The pre-cut technique was performed after failure of multiple cannulation attempts. RESULTS: Bile duct clearance was achieved in 344 (89.1%) cases, however the success rate would increase to 95.1%, if the cases, which endoscopic stone extraction was not feasible, were excluded. Pre-cut was performed in 31 (8.03%) patients, and 11 of them presented some procedure-related complication, while the complication rate of standard sphincterotomy was 3.9% (relative risk = 8.4; 95% confidence interval = 4.2-16.7). Overall complication rate was 6.7% (26 out of 386)--pancreatitis = 13, bleeding = 9, acute cholecystitis = 2, cholangitis = 1, guide-wire-related choledochal perforation = 1. Thirty-day mortality was 1.55% (n = 6), but procedure-related mortality was 0.25% (n = 1). CONCLUSIONS: Endoscopic papillotomy is a safe and effective procedure for patients with symptomatic choledocholithiasis. The pre-cut procedure increases the complication rate of the endoscopic approach, and should be restricted to cases, in which an endoscopic intervention is mandatory.

Effects of L-arginine on the kidney levels of malondialdehyde in rats submitted to renal ischaemia-reperfusion.

OBJECTIVE: To evaluate the effects of L-arginine, a nitric oxide donor, on kidney levels of malondialdehyde (MDA, a product of cellular lipid peroxidation), serum creatinine levels, and urinary volume in rats undergoing unilateral renal ischaemia-reperfusion. MATERIALS AND METHODS: Wistar rats (117) were randomly distributed into three experimental groups (of four subgroups each) in which were assessed renal cell-lipid peroxidation (kidney levels of MDA), serum creatinine levels and urinary volume. The rats underwent unilateral nephrectomy followed by contralateral renal ischaemia-reperfusion with or with no pretreatment with L-arginine (200 mg/kg) given intraperitoneally. RESULTS: Pretreatment with L-arginine caused significantly higher kidney levels of MDA than in the untreated group (P < 0.05). Furthermore, L-arginine given before surgery attenuated the increase in serum creatinine and significantly increased urinary volume in rats subjected to renal ischaemia-reperfusion (P < 0.05). CONCLUSION: L-arginine tended to be of benefit for renal function during renal ischaemia-reperfusion in rats. Pretreatment with L-arginine (200 mg/kg intraperitoneally) seems to increase the renal damage by increasing kidney levels of MDA.

Role of the L-arginine/nitric oxide pathway in renal ischaemia-reperfusion in rats.

OBJECTIVE: To study the role of the L-arginine/nitric oxide (NO) pathway during renal ischaemia-reperfusion in rats. DESIGN: Randomised experimental study. SETTING: Teaching hospital, Brazil. ANIMALS: 97 male Wistar rats randomly assigned to 4 groups for the assessment of renal dysfunction and to 6 groups for the assessment of the oxidative stress induced on renal cell membranes by ischaemia-reperfusion. INTERVENTIONS: The animals underwent sham-operation or renal ischaemia-reperfusion (n = 9 each) with or without pretreatment with L-arginine (a NO donor) or L-NAME (N(omega)-nitro-L-arginine methyl ester--an inhibitor of NO production) (n = 10 each). MAIN OUTCOME MEASURES: Serum creatinine concentrations and oxidative stress by chemiluminescence initiated by the tert-butyl hydroperoxide technique. RESULTS: Renal ischaemia-reperfusion significantly worsened renal dysfunction and increased oxidative stress in the ischaemia-reperfusion group after 24 and 96 hours of reperfusion compared with the control group (p < 0.05). Pretreatment with L-NAME slightly but not significantly increased serum creatinine concentrations after 24 and 96 hours of reperfusion together with activity of reactive oxygen species during renal ischaemia-reperfusion. L-arginine also significantly protected renal function and reduced the increment in the amount of chemiluminescence induced by giving L-NAME during 24 and 96 hours of reperfusion (p < 0.05). CONCLUSION: The L-arginine/NO pathway seems to have a slightly protective effect on the kidney after renal ischaemia-reperfusion injury in rats. These results need to be confirmed by studies in human beings.

Prevalence of Peyronie's disease in men over 50-y-old from Southern Brazil.

The pathogenesis of Peyronie's disease still remains an enigma and few epidemiological studies are available. The purpose of this study was to determine the prevalence of Peyronie's disease in males older than 50 y. From 26 to 30 July 1998, 1071 men attended the 'Prostate Cancer Awareness Week of Santa Casa Hospital, Porto Alegre, Brazil'. In the prostate exam they also consented to be screened for Peyronie's disease. They underwent the 5-item International Index of Erectile Function (IIEF-5) questionnaire for evaluation of the erectile condition. The presence of a well-defined plaque in the penis was the diagnostic criterion for Peyronie's disease. The men were examined by five senior residents, under supervision by the staff Urologist. Men younger than 50 y as well as patients under intracavernous injection therapy for erectile dysfunction were excluded from the study. Chi2 test was used for statistical analysis. Nine hundred and fifty-four (89.1%) out of the 1071 men with a mean age of 62 y (ranging from 52 to 77) were included in the study. Peyronie's disease plaques were found in 35 men (3.67%). Eight hundred and forty-five (88.6%) were Caucasians. There was no significant statistical difference regarding age (P > 0.05). The presence of erectile dysfunction in the men with Peyronie's disease and without this condition, was 68.6% and 53.5%, respectively (P > 0.05). From this data we can conclude that the prevalence of Peyronie's disease is higher than in formerly reported studies. Further observations should be carried out in different communities and in other groups of patients in order to confirm our results.

The effects of allopurinol in hepatic ischemia and reperfusion: experimental study in rats.

BACKGROUND/AIMS: Some studies have shown that postischemic hepatic dysfunction is mainly due to oxygen free radicals that are generated by xanthine oxidase. The present study was undertaken to determine the effect of allopurinol, an inhibitor of xanthine oxidase, on oxidative stress, liver injury and histologic alterations induced by hepatic ischemia-reperfusion in rats. METHODS: One hundred and sixty Wistar rats were used and divided into three groups. Group 1: sham operation; group 2: 50 min of ischemia followed by 1 h of reperfusion, and group 3: pretreatment with allopurinol and 50 min of ischemia followed by 1 h of reperfusion. The effect of allopurinol was evaluated by plasma levels of alanine aminotransferase and aspartate aminotransferase, histopathologic studies, and lipid peroxidation measured by the thiobarbituric acid reactive substances method and chemiluminescence initiated by tert-butyl hydroperoxide technique. RESULTS: Ischemia followed by reperfusion promoted an increase in lipid peroxidation of the hepatic cells when compared to the sham-operated group (p<0.05). This increase was attenuated in the group treated with allopurinol (p< 0.05). Allopurinol also showed a protective effect on hepatocellular necrosis (p<0.05), and the plasma levels of liver enzymes returned earlier to the normal range in rats pretreated with allopurinol in comparison to those that did not receive the drug (p<0.05). CONCLUSIONS: Allopurinol exerted a protective effect on hepatic ischemia and reperfusion in rats. The administration of this drug prior to liver operations should be considered to be submitted to trials in humans.

Penile straightening with crural graft of the corpus cavernosum.

PURPOSE: We present a surgical alternative to penile straightening in Peyronie's disease that avoids penile shortening by using tissue from the crural segment of the corpora cavernosa as a graft. MATERIALS AND METHODS: We treated 7 patients with stable Peyronie's disease and satisfactory penile rigidity but significant curvature that precluded intercourse with this technique. An incision is made in the fibrous area and after stretching the gap is covered with a graft removed from the crural segment of the corpora cavernosa. RESULTS: In 6 of the 7 men straightening was satisfactory but in 1 it was not complete. No patient reported worse penile rigidity postoperatively. Donor site healing was uneventful. CONCLUSIONS: Use of tissue from the corpus cavernosum to correct penile curvature is effective. However, our results are preliminary, and long-term effectiveness and safety must be confirmed in a larger number of cases.

Experience with early catheter removal after radical retropubic prostatectomy.

PURPOSE: We tested the hypothesis that early catheter removal may be accomplished safely after radical prostatectomy. MATERIALS AND METHODS: Cystography on postoperative day 4 or 5 in 42 of 67 consecutive patients who underwent radical retropubic prostatectomy revealed no extravasation in 30 and the urethral catheter was removed (group 1). The control group included 25 patients who did not undergo cystography, and the catheter was removed 14 days postoperatively (group 2). RESULTS: Immediate and late continence was achieved in 14 (46.7%) and 25 (83.3%) cases in group 1, and in 8 (32%) and 22 (88%) cases in group 2, respectively (p>0.05). Catheterization was performed easily without any endoscopic or surgical procedure in 2 patients (6.7%) in group 1 who presented in urinary retention after catheter removal. Wound infection and pelvic abscess developed in 1 case (3.3%). There were no late complications. In group 2 urinary retention developed in 1 patient (4%), wound infection in 1 (4%) and hematuria in 1 (4%). Two patients (8%) had late vesical neck contracture at 4 and 10 months, respectively, which required urethrotomy in 1. In 1 patient (4%) a stricture in the anterior urethra was dilated. CONCLUSIONS: Our study shows that early catheter removal may be accomplished safely in most patients after radical retropubic prostatectomy, and was not associated with a higher complication rate.

Effects of ischemia and reperfusion on oxidative stress in hepatic cirrhosis induced by carbon tetrachloride in rats.

The present study was undertaken to determine the effect of ischemia and reperfusion on oxidative stress in hepatic cirrhosis induced by carbon tetrachloride (CCl4) in rats by the evaluation of lipid peroxidation products (LPO). Cirrhosis of the liver was induced by CCl4 administration. This drug was dissolved in mineral oil and the control group received only mineral oil intraperitoneally. Forty-five minutes of ischemia followed by one hour of reperfusion were performed. LPO products were evaluated by the thiobarbituric acid reactive substances method (TBARS) and chemiluminescence initiated by tert-butyl hydroperoxide technique (CL). The liver was submitted to histologic evaluation to check whether cirrhosis was present. The results demonstrated that ischemia-reperfusion caused an increase of LPO products in cirrhotic rats when compared to the control group (p < 0.05). Hepatic cirrhosis was present in all animals treated with CCl4 and no significant histologic alterations were observed in the control group. According to this study, we can conclude that the effect of ischemia and reperfusion in a rat model of hepatic cirrhosis caused a significant increase of the hepatic-levels of LPO products when compared to the noncirrhotic livers.

Protective effect of allopurinol in the renal ischemia--reperfusion in uninephrectomized rats.

The effect of allopurinol (an inhibitor of xanthine oxidase) on oxidative stress, renal dysfunction, and histologic alterations was evaluated during the renal ischemia--reperfusion in uninephrectomized rats. Renal malondialdehyde and serum creatinine levels significantly increased after renal ischemia--reperfusion. However, the pretreatment with allopurinol demonstrated a protector effect in these parameters. Renal ischemia--reperfusion provoked a significant renal damage in the operated group. Tubular atrophy and interstitial fibrosis were attenuated by allopurinol when given prior to the surgery. In our study, allopurinol had a strong tendency to exert a beneficial effect during renal ischemia--reperfusion in uninephrectomized rats.

Is there any association between Peyronie's disease and serum collagen markers?

Several theories regarding the pathogenesis of Peyronie's disease have been investigated under many clinical conditions. We have investigated the association of Peyronie's disease with the most common markers of collagen disease. Several serum markers of collagen disease (mucoproteins, C-reactive protein, antinuclear antibody, rheumatoid factor, lupus erythematosus cells, proteinograms) of 30 patients with Peyronie's disease were compared with those obtained from 30 patients, matched for age, with other urological conditions unrelated to the penis. Mucoproteins were altered in 66.7% of patients of the Peyronie's disease group and in 46.7% of the control patients (P>0.05). C-reactive protein was altered in 23.3% of the Peyronie's disease patients and in 13.3% of the control patients (P>0.05). Antinuclear antibody (ANA) was reactive in 16.7% of the tested group and in 6.7% of the control group (P>0.05). The rheumatoid factor was elevated in 6.7% of the patients from both groups (P>0.05). LE cells were normal in all the patients in our study. No statistical significance between the two groups was found in the protein electrophoresis test. Only the Waaler-Rose test (rheumatoid hemagglutination test) was statistically significant in our study (P<0.05). We have not found any significant association between the serum markers of collagen diseases in patients with Peyronie's disease, except the rheumatoid hemagglutination test (Waaler-Rose).

Tamoxifen versus placebo in the treatment of Peyronie's disease.

PURPOSE: We evaluated the effects of oral tamoxifen and placebo in patients with Peyronie's disease. MATERIALS AND METHODS: We selected 25 patients with Peyronie's disease who did not have calcified plaque for treatment in the andrology outpatient clinic. A medical history was obtained, and physical examination, penile x-ray, penile ultrasound and pharmacologically induced erection with prostaglandin E1 were performed. Patients were randomly divided into group 1--those who received 20 mg. tamoxifen twice daily for 3 months and group 2--those who received placebo for the same period. The same evaluations were done 4 months later and results were compared. Qualitative (chi-square test) and quantitative (Student's t test) results were analyzed using the Yates correction factor with p <0.05 considered significant. RESULTS: Pain subsided in 66.6 and 75% of the patients treated with tamoxifen and placebo, respectively (p >0.05). In groups 1 and 2 a reduction in the penile deformity was noticed by 46.1 and 41.7% of the patients (p >0.05), and a decrease in plaque size was noticed by 30.7 and 25%, respectively. On the other hand, objective measurements did not reveal any difference in plaque area or curvature angle. CONCLUSIONS: This study did not show significant improvement in pain, curvature or plaque size in patients with Peyronie's disease who were treated with tamoxifen compared with those treated with placebo.

The role of colchicine in prevention of hepatic cirrhosis induced by carbon tetrachloride.

BACKGROUND/AIMS: The present study was undertaken to determine whether colchicine has a beneficial effect in the prevention of hepatic cirrhosis when it is given simultaneously with CCl4. METHODOLOGY: Wistar rats were employed as experimental animals and divided into 6 groups: Group I received saline solution, Group II, saline solution and mineral oil; Group III, colchicine (10 micrograms/100 g) and mineral oil; Group IV, colchicine (10 micrograms/100 g) and CCl4; Group V, colchicine (5 micrograms/100 g) and CCl4; and, Group VI received saline solution and CCl4. The effect of colchicine was evaluated by liver function tests, serum total proteins, electrolytes and histological evaluation. RESULTS: The results demonstrated higher values of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and total bilirubin in groups IV and V when compared with group VI (p < 0.05). No difference between group VI and groups IV and V was observed in histological evaluation, serum total proteins and electrolytes (p < 0.05). CONCLUSIONS: Colchicine, as given in this study, did not have any protective effect in the prevention of cirrhosis induced by carbon tetrachloride.

Pancreatic fistula after pancreaticoduodenectomy: a comparison between patients with periampullary tumors and chronic pancreatitis.

BACKGROUND/AIMS: Whether the frequency of anastomotic leak after pancreaticoduodenectomy for benign diseases is greater than for malignant conditions and whether fistula development is associated with surgical mortality remains controversial. The purpose of this study is to compare the incidence of anastomotic leak in patients operated on for chronic pancreatitis and periampullary tumors. METHODOLOGY: The authors retrospectively reviewed the charts of 67 patients (46 males, 21 females, mean age 47 years) submitted to pancreaticoduodenectomy for chronic pancreatitis and periampullary tumors between 1990 and 1996. RESULTS: In 44 patients with periampullary cancers, pancreatic fistula developed in 13 (29%) cases, and in 6 (26%) of the 23 patients with chronic pancreatitis (p>0.05). Of the 19 patients who developed this complication, 5 (26.3%) died, and in the remaining 48 cases, there was only one (2.1%) death (p<0.05). CONCLUSION: The frequency of pancreatic fistula after pancreaticoduodenectomy in patients with periampullary tumors and chronic pancreatitis is not different, but the presence of a fistula is strongly involved in postoperative mortality.

Therapeutic effects of high dose yohimbine hydrochloride on organic erectile dysfunction.

PURPOSE: We evaluated men with organic erectile dysfunction treated with placebo and high dose oral yohimbine hydrochloride. MATERIALS AND METHODS: We selected 22 patients with organic erectile dysfunction (mean age 58 years) for treatment in the andrology outpatient clinic. These patients had been previously undergone neurological, vascular, hormonal and psychological testing, and were treated during an equal period of 30 days with placebo and daily single dose oral 100 mg. yohimbine. The response to treatment was evaluated via a questionnaire that comprised the outcome items of complete--normal penile rigidity enabling vaginal penetration, partial--erection improved but not sufficiently for appropriate vaginal penetration, none--no improvement and worse--erection deteriorated. The patients consented to treatment after being told of the severe adverse effects that might occur. RESULTS: The most common side effects were anxiety, increase in cardiac frequency, increased urinary output and headache but in no case was treatment discontinued. Of the patients 3 (13.6%) and 12 (54.5%) reported complete or partial response to treatment, respectively. However, statistical analysis disclosed no significant difference when yohimbine was compared to placebo (p < 0.05). CONCLUSIONS: Oral 100 mg. single dose daily yohimbine promotes no improvement in patients with organic erectile dysfunction.