Prostate Transition Zone Fibrosis is Associated with Clinical Progression in the MTOPS Study

PURPOSE

Medications targeting androgen receptor activity (eg finasteride) or smooth muscle contractility (eg doxazosin) do not resolve lower urinary tract symptoms indicative of lower urinary tract dysfunction in an important subgroup of men. Recently fibrosis has been implicated as another pathobiology contributing to male lower urinary tract symptoms but to our knowledge no systematic studies have been done to assess fibrosis in the context of medical treatment. We determine whether fibrotic changes in the prostate transition zone are associated with an increased risk of clinical progression in participants treated with doxazosin, finasteride or finasteride plus doxazosin in the MTOPS (Medical Therapy of Prostatic Symptoms) study.

MATERIALS AND METHODS

Transition zone biopsy tissues from men who did or did not experience clinical progression on placebo, doxazosin, finasteride or combination therapy were assessed for collagen content and architectural changes using picrosirius red birefringence and CT-FIRE (Curvelet Transform-Fiber Extraction) analysis. Correlations were made with annotated demographic and clinical data. Statistical analyses were done with the Pearson correlation coefficient, ANOVA and the t-test.

RESULTS

High levels of wavy, aligned prostate transition zone collagen significantly correlated with an increased risk of clinical progression among MTOPS trial participants treated with doxazosin plus finasteride, particularly those with a high body mass index.

CONCLUSIONS

Fibrotic changes in the prostate transition zone are associated with an increased risk of clinical progression in men treated with doxazosin plus finasteride. Antifibrotic therapeutics might provide a new treatment approach in men with lower urinary tract dysfunction who do not respond to current medical treatment approaches.

A case of normotensive incidentally discovered adrenal pheochromocytoma

Pheochromocytomas are catecholamine-producing neuroendocrine tumors that arise from the adrenal medulla. The clinical presentation includes headache, palpitation, and hypertension, but pheochromocytomas are sometimes clinically silent. The present case highlights the importance of biochemical testing for pheochromocytoma in patients with adrenal incidentaloma, even if they are completely normotensive and asymptomatic.

Successful management of a third-trimester pregnancy complicated by pheochromocytoma: case report

Pheochromocytoma (PH) is a tumor that arises from chromaffin cells of the adrenal medulla. Though being this benign neoplasm very rare in pregnancies, lack of treatment nevertheless causes high mortality rates for both the mother and the fetus. Classic symptoms related to PH are hypertension, abdominal pain, diaphoresis, and headache; but it can be easily misdiagnosed as gestational hypertension or preeclampsia. Its appearance is sporadic, but there are some genetic disorders that favor its onset (e.g. MEN 2A and 2B). Individual management is needed, because no single protocol is suitable in such a complex and rare condition. In this paper we describe our experience in the clinical and surgical management of a young pregnant patient affected by PH, and in particular the specific and unique pharmacological treatment with doxazosin, the use of corticosteroids and a close monitoring of fetal well-being, which proved being an effective approach.

A preliminary investigation into the effects of doxazosin on cognitive functioning in tobacco-deprived and -satiated smokers

OBJECTIVE

To test the effects of doxazosin, an α1 antagonist, on cognitive functioning during tobacco withdrawal in smokers.

METHODS

Participants (n = 35) were randomly assigned to receive placebo, 4-mg/day, or 8-mg/day doxazosin. They completed a continuous performance task and self-reported their withdrawal symptoms at baseline and twice following a medication titration period: once in a tobacco-deprived state and again in a nondeprived state. Ability to resist smoking was assessed using a laboratory smoking-lapse paradigm.

RESULTS

Participants showed poorer cognitive performance on most measures taken from the continuous performance task when tobacco deprived. Eight-mg/day doxazosin improved inhibitory control during the nondeprivation session but did not affect sustained attention or reaction time. Participants receiving doxazosin reported fewer withdrawal symptoms during deprivation than those on placebo. Those showing the greatest improvement of inhibitory control under doxazosin were better able to resist smoking (i.e., latency to smoke) during a smoking lapse task. Self-reported withdrawal symptoms also were negatively associated with time to smoking.

CONCLUSIONS

Doxazosin reduced symptoms of tobacco withdrawal according to self-report and cognitive assessment and improved inhibitory control above predrug levels. This research identifies potential mechanisms by which doxazosin might improve smoking outcomes.

Three-Year Treatment Outcomes of Water Vapor Thermal Therapy Compared to Doxazosin, Finasteride and Combination Drug Therapy in Men with Benign Prostatic Hyperplasia: Cohort Data from the MTOPS Trial

PURPOSE

We evaluated the long-term outcomes of treatment of lower urinary tract symptoms due to benign prostatic hyperplasia to compare a 1-time water vapor thermal therapy procedure with daily medical therapy in cohorts from the MTOPS (Medical Therapy of Prostatic Symptoms) study.

MATERIALS AND METHODS

Results in the treatment arm of a randomized, controlled trial of thermal therapy using the Rezūm® System were compared to MTOPS subjects treated with doxazosin and/or finasteride. Evaluations were restricted to medical therapy subjects, representing 1,140 of the original 3,047 (37.4%), with a prostate volume of 30 to 80 cc and an International Prostate Symptom Score of 13 or greater to include men who met key criteria of the Rezūm and MTOPS trials. Outcomes were compared during 3 years for symptom changes and clinical progression rates.

RESULTS

Thermal therapy improved symptom scores by approximately 50% throughout 36 months (p <0.0001). Symptom improvement was greater than with either drug alone but similar to that of combination drugs (p ≤0.02 and 0.73, respectively). The peak flow rate improved 4 to 5 ml per second after thermal therapy and doxazosin while thermal therapy was superior to finasteride and combination drugs for 24 and 12 months (p <0.001 and <0.01, respectively). Observed rates of clinical progression during 3 years corroborate these outcomes with approximately 5 times greater progression for any medical therapy vs a single thermal therapy procedure.

CONCLUSIONS

A single water vapor thermal therapy procedure provided effective and durable improvements in symptom scores with lower observed clinical progression rates compared to daily long-term use of pharmaceutical agents.

Effects of the inverse alpha-agonist doxazosin in allergic rhinitis

BACKGROUND

We examined the paradoxical hypothesis that the alpha-receptor inverse agonist doxazosin might produce beneficial effects in allergic rhinitis.

OBJECTIVES

To evaluate single and chronic dosing effects of doxazosin on nasal airflow and symptoms in allergic rhinitis.

METHODS

Fifteen patients randomized to receive 3-5 weeks of oral doxazosin 4 mg daily or placebo in crossover fashion. Measurements were taken at baseline and after first and last doses.

RESULTS

There was a fall in peak nasal inspiratory flow (PNIF) between baseline vs. first dose of doxazosin: mean difference -19 L/min (95% CI -35 to -2) P = 0.03, with recovery between first and last doses: 21 L/min (95% CI 7-34) P = 0.006. Nasal visual analogue scale (VAS) and blockage scores were worse between baseline vs. first dose of doxazosin: mean difference VAS -10 mm (95% CI -18 to -2) P = 0.02, blockage -0.7 (95% CI -1.3 to -0.1) P = 0.02, with recovery between first and last doses: VAS 15 mm (95% CI 4-25) P = 0.009, blockage 1.1 (95% CI 0.5-1.6) P = 0.001. The oxymetazoline dose-response for PNIF was blunted after single vs chronic dosing with doxazosin: mean difference -17 L/min (95% CI -30 to -4) P = 0.01. Heart rate and diastolic blood pressure showed the same pattern. There was a significant difference between doxazosin and placebo for nasal blockage score and heart rate after single but not chronic dosing.

CONCLUSIONS

There was a disconnect between single and chronic dosing effects of doxazosin for nasal symptoms, oxymetazoline response and cardiovascular outcomes, in turn suggesting alpha-1 receptor up-regulation.

The influence of doxazosin on the contractility of the urinary bladder in female pigs with experimentally induced cystitis

The present in vitro study investigated the influence of doxazosin on the contractility of the urinary bladder in female pigs with experimentally induced cystitis. Fifteen juvenile female piglets (18-20 kg body weight) were randomly assigned into three groups (n=5 animals each): i) control (clinically healthy animals, without doxazosin treatment), ii) animals with induced inflammation of the urinary bladder, but without doxazosin treatment (experimental group I) and iii) animals with inflamed bladder, treated orally with doxazosin (0.1 mg/kg body weight for 30 days; experimental group II). Thereafter, the pigs were sacrificed and strips of the bladder trigone were suspended in organ baths. The tension and amplitude of the smooth muscles was measured before and after exposition to 5-hydroxytryptamine (5-HT; 10-6-10-4 M), acetylocholine (ACh; 10-5-10-3 M) and norepinephrine (NE; 10-9-10-7 M). 5-HT caused an increase in the tension of contractions in all the groups and the amplitude in the experimental groups, however, the effect was higher in the experimental group I than in group II as compared to that found in the pre-treatment period. ACh caused an increase in the tension in the control group and a decrease in the amplitude in both experimental groups; these changes significantly differed between the control and doxazosin-treated group. NE caused a decrease in the tension in both experimental groups and amplitude in all the groups, however, the effect was most strongly expressed in doxazosine-treated group. The present study has revealed that long-term administration of doxazosin causes a desensitization of the detrusor smooth muscle to in vitro applied mediators in the autonomic nervous system.

Comparison of phenoxybenzamine and doxazosin in perioperative management of patients with pheochromocytoma

BACKGROUND

Adrenalectomy with preoperative pharmacological preparation is strongly recommended in patients diagnosed with pheochromocytoma, in order to prevent perioperative complications.

AIM

To compare phenoxybenzamine (PhB) and doxazosin (DOX) in terms of perioperative haemodynamic status in patients with pheochromocytoma, who have been prepared for adrenalectomy.

METHODS

Retrospective analysis of 44 patients with pheochromocytoma (aged 16-80 years, 29 females) who underwent adrenalectomy. Patients were divided into two groups: 35 patients on DOX and nine patients on PhB.

RESULTS

Mean time of preparation for surgery was 38.8 days in the DOX group and 18.3 days in the PhB group (p = 0.04). No statistically significant differences between the DOX and PhB groups in intraoperative blood pressure (BP) fluctuations were found: < 170/100 mm Hg (34% vs. 44%, respectively, p = 0.42), ≥ 200/110 mm Hg (40% vs. 22%, respectively, p = 0.28). Mean greatest intraoperative systolic BP (195 ± 53 vs. 166 ± 42 mm Hg, p = 0.21) and diastolic BP (98 ± 20 vs. 89 ± 46 mm Hg, p = 0.21), and mean lowest intraoperative systolic BP (87 ± 13 vs. 79 ± 17 mm Hg, p = 0.25) and diastolic BP (49 ± 8 vs. 46 ± 12 mm Hg, p = 0.60) were not different between the DOX and PhB groups, respectively. Sodium nitroprusside was administrated in 30% DOX vs. 11% PhB patients (p = 0.25). Laparoscopic surgery was conducted in 97% DOX vs. 89% PhB patients (p = 0.64). Postoperative BP drop below 90/60 mm Hg was noted in 48% of the DOX vs. 43% of the PhB group (p = 0.56). Negative correlation was found between the length of DOX administration with maximal intraoperative systolic BP (r = -0.45, p = 0.006) and diastolic BP (r = -0.39, p = 0.019).

CONCLUSIONS

There are no clinically relevant differences between patients with pheochromocytoma, who have been prepared for adrenalectomy with DOX or PhB.

Effect of doxazosin on stress reactivity and the ability to resist smoking

Preclinical findings support a role for α1-adrenergic antagonists in reducing nicotine-motivated behaviors, but these findings have yet to be translated to humans. The current study evaluated whether doxazosin would attenuate stress-precipitated smoking in the human laboratory. Using a well-validated laboratory analogue of smoking-lapse behavior, this pilot study evaluated whether doxazosin (4 and 8 mg/day) versus placebo attenuated the effect of stress (vs neutral imagery) on tobacco craving, the ability to resist smoking and subsequent ad-libitum smoking in nicotine-deprived smokers ( n=35). Cortisol, adrenocorticotropin, norepinephrine, epinephrine, and physiologic reactivity were assessed. Doxazosin (4 and 8 mg/day vs placebo) decreased cigarettes per day during the 21-day titration period. Following titration, doxazosin (4 and 8 mg/day vs placebo) decreased tobacco craving. During the laboratory session, doxazosin (8 mg/day vs placebo) further decreased tobacco craving following stress versus neutral imagery. Doxazosin increased the latency to start smoking following stress, and reduced the number of cigarettes smoked. Dosage of 8 mg/day doxazosin increased or normalized cortisol levels following stress imagery and decreased cortisol levels following neutral imagery. These preliminary findings support a role for the noradrenergic system in stress-precipitated smoking behavior, and support further development of doxazosin as a novel pharmacotherapeutic treatment strategy for smoking cessation.

Role of the α1 blocker doxazosin in alcoholism: a proof-of-concept randomized controlled trial

Evidence suggests that the norepinephrine system represents an important treatment target for alcohol dependence (AD) and the α1 -blocker prazosin may reduce alcohol drinking in rodents and alcoholic patients. The α1 -blocker doxazosin demonstrates a more favorable pharmacokinetic profile than prazosin, but has never been studied for AD. A double-blind placebo-controlled randomized clinical trial was conducted in AD individuals seeking outpatient treatment. Doxazosin or matched placebo was titrated to 16 mg/day (or maximum tolerable dose). Drinks per week (DPW) and heavy drinking days (HDD) per week were the primary outcomes. Family history density of alcoholism (FHDA), severity of AD and gender were a priori moderators. Forty-one AD individuals were randomized, 30 (doxazosin = 15) completed the treatment phase and 28 (doxazosin = 14) also completed the follow-up. There were no significant differences between groups on DPW and HDD per week. With FHDA as a moderator, there were significant FHDA × medication interactions for both DPW (pcorrected  = 0.001, d = 1.18) and HDD (pcorrected  = 0.00009, d = 1.30). Post hoc analyses revealed that doxazosin significantly reduced alcohol drinking in AD patients with high FHDA and by contrast increased drinking in those with low FHDA. Doxazosin may be effective selectively in AD patients with high FHDA. This study provides preliminary evidence for personalized medicine using α1 -blockade to treat AD. However, confirmatory studies are required.

An Evaluation of the Efficacy of Selective Alpha-Blockers in the Treatment of Children with Neurogenic Bladder Dysfunction--Preliminary Findings

The aim of this study was to assess the usefulness of selective α1-blockers in children with neurogenic urinary tract dysfunctions and increased leak point pressure (LPP). 14 children from age 6 to 16 years with neurogenic urinary tract dysfunctions (neurogenic bladder) and LPP > 40 cm H₂O were enrolled in the study. All patients received a selective α1-blocker (doxazosin) for 6-8 weeks with an initial dosage of 0.03 mg/kg. During the observation period the continuation of oral anticholinergics, Clean Intermittent Catheterization (CIC), observation of "urinary dryness" and urinary incontinence periods were recommended. Patients were scheduled for a follow-up visit and urodynamic investigation after 6-8 weeks after the doxazosin therapy was started. In 4 patients, urine leakage occurred at lower pressures; in 9 patients, no significant changes in urine leak point pressures were detected; in 3 patients, there was a significant increase in the bladder capacity; in one patient, deterioration in continence was noted. The differences both in LPP and LPV before and after the treatment were not statistically significant. Our observations are consistent with the conclusions from other studies and showed no evident efficacy of doxazosin in children with neurogenic bladder.

Time Course of Incident Adverse Experiences Associated with Doxazosin, Finasteride and Combination Therapy in Men with Benign Prostatic Hyperplasia: The MTOPS Trial

PURPOSE

We examined first (incident) reports of selected adverse experiences associated with medical therapy in men with lower urinary tract symptoms secondary to benign prostatic hyperplasia.

MATERIALS AND METHODS

We studied the 6 most common adverse experiences, including nonsexual function related experiences (dizziness, orthostatic hypotension and weakness) and sexual function related experiences (impotence, decreased libido and abnormal ejaculation) reported in the MTOPS (Medical Therapy of Prostatic Symptoms) Study. A total of 3,047 men were randomized to placebo, doxazosin, finasteride or combination therapy and followed for a mean duration of 4.5 years. We compared the incidence rates of adverse experiences at year 1 to the rates thereafter.

RESULTS

For each assigned treatment group, the incidence rates were significantly higher for all 6 adverse experiences examined at year 1 compared with the rates thereafter. Men assigned to combination therapy experienced the highest rates at year 1 with rates 3.4-fold to 10.6-fold higher than rates after year 1. The incidence rates for orthostatic hypotension and dizziness were significantly higher in the doxazosin and combination therapy groups compared with the placebo group at year 1. The incidence rates of the 3 examined sexual function related adverse experiences were significantly higher in the finasteride and combination therapy groups than in the placebo group at year 1.

CONCLUSIONS

Rates of the first report of sexual function related and other adverse experiences associated with doxazosin, finasteride and combination therapy were greatest during year 1 of treatment. These patterns should be considered by patients and physicians when treatment for lower urinary tract function is initiated with these drugs.

[On prevention of post-surgery acute urinary retention]

The article highlights the issues of prevention of acute urinary retention after surgery. The authors present results of a study on the efficacy and safety of 1-blockers for the prevention of acute urinary retention after surgery. The results imply that the use of 1-blockers in pre- and postoperative period can significantly reduce the risk of postoperative ischuria, contribute to independent urination after a single urinary catheterization in patients who experience urinary retention, improve the postoperative period and promote recovery of patients.

Influence of doxazosin on biosynthesis of S100A6 and atrial natriuretic factor peptides in the heart of spontaneously hypertensive rats

Hypertension frequently results in severe complications in cardiovascular system and histopathological changes in the heart. To better understand the cellular processes and signaling pathways responsible for the proper functioning of the heart, we decided to check whether doxazosin affects the density of structures containing S100A6 and atrial natriuretic factor in the heart of spontaneously hypertensive rats. The aim of this study is to find differences in the density of the structures containing S100A6 and atrial natriuretic factor in the heart of spontaneously hypertensive rats treated with doxazosin compared to untreated animals. Fragments of heart were collected from five spontaneously hypertensive rats and five spontaneously hypertensive rats receiving doxazosin for six weeks (dose 0.1 mg per 1 kg of body weight). On the paraffin sections S100A6 and atrial natriuretic factor peptides were localized in the heart using immunohistochemistry. Positive immunohistochemical reaction for S100A6 was observed in atrial and ventricular cardiomyocytes and in the coronary vasculature. In the heart of hypertensive rats treated with doxazosin the S100A6 immunoreactivity was significantly lower compared to untreated animals. Immunodetection of atrial natriuretic factor in the heart of rats confirmed presence of peptide in atrial myocardium. Delicate atrial natriuretic factor-immunoreactivity was observed also in few ventricular cardiomyocytes. The atrial natriuretic factor-immunosignal was significantly weaker in hearts of hypertensive rats receiving doxazosin compared to spontaneously hypertensive rats untreated. Since we found that doxazosin reduces the levels of S100A6 and atrial natriuretic factor peptides in the heart of spontaneously hypertensive rats, it can be assumed that cardiovascular disorders that occur in hypertension may be associated with disturbances of cellular processes and signaling pathways.

Enantioselective pharmacokinetics of doxazosin and pharmacokinetic interaction between the isomers in rats

In this study, the stereoselective pharmacokinetics of doxazosin enantiomers and their pharmacokinetic interaction were studied in rats. Enantiomer concentrations in plasma were measured using chiral high-pressure liquid chromatography (HPLC) with fluorescence detection after oral or intravenous administration of (-)-(R)-doxazosin 3.0 mg/kg, (+)-(S)-doxazosin 3.0 mg/kg, and rac-doxazosin 6.0 mg/kg. AUC values of (+)-(S)-doxazosin were always larger than those of (-)-(R)-doxazosin, regardless of oral or intravenous administration. The maximum plasma concentration (Cmax ) value of (-)-(R)-doxazosin after oral administration was significantly higher when given alone (110.5 ± 46.4 ng/mL) versus in racemate (53.2 ± 19.7 ng/mL), whereas the Cmax value of (+)-(S)-doxazosin did not change significantly. The area under the curve (AUC) and Cmax values for (+)-(S)-doxazosin after intravenous administration were significantly lower, and its Cl value significantly higher, when given alone versus in racemate. We speculate that (-)-(R)-doxazosin increases (+)-(S)-doxazosin exposure probably by inhibiting the elimination of (+)-(S)-doxazosin, and the enantiomers may be competitively absorbed from the gastrointestinal tract. In conclusion, doxazosin pharmacokinetics are substantially stereospecific and enantiomer-enantiomer interaction occurs after rac-administration.

The antihypertension drug doxazosin suppresses JAK/STATs phosphorylation and enhances the effects of IFN-α/γ-induced apoptosis

Doxazosin, a commonly prescribed treatment for patients with benign prostatic hyperplasia, serves as an α1-blocker of the adrenergic receptors. In this study, we calculated its effect on the ovarian carcinoma cells. Doxazosin induces dose-dependent growth suppression and is additively activated through IFN-α or IFN-γ stimulation. They both enhanced G1 phase arrest, as well as the activity of caspase-3, and the reduction of cyclin D1 and CDK4 protein levels. Doxazosin growth suppression was abolished either by the Janus family of tyrosine kinase (JAK) or the signal transducer and activator of transcription (STAT) inhibitor treatment. The activity of JAK/STAT was dependent on the level of doxazosin, suggesting a requirement of doxazosin for the activation of JAK/STAT. Furthermore, doxazosin plus IFN-α or doxazosin plus IFN-γ additively suppressed the activation of the JAK/STAT signals through phosphorylation of JAK and STAT, thus affecting the activation of subsequent downstream signaling components PI3K, mTOR, 70S6K, and PKCδ. In vivo study demonstrated that doxazosin significantly suppressed tumor growth in an ovarian cancer cell xenograft mouse model, inducing apoptotic cell death by up-regulating the expression of p53, whereas c-Myc expression was markedly reduced. Our data indicate that doxazosin can modulate the apoptotic effects of IFN-α- and IFN-γ through the JAK/STAT signaling pathways. Collectively, we indicate that this action may be a potent chemotherapeutic property against ovarian carcinoma.

α-adrenergic blockers for the treatment of lower-urinary-tract symptoms and dysfunction in women

OBJECTIVE

To evaluate the efficacy and safety of α-adrenergic blockers in the treatment of female lower-urinary-tract symptoms and dysfunction.

DATA SOURCES

Literature searches were conducted using EMBASE (1974 to January 2014), International Pharmaceutical Abstracts (1970 to January 2014), and MEDLINE (1946 to January 2014) to identify clinical trials evaluating the effects of α-adrenergic blockers in the treatment of women with lower-urinary-tract dysfunction. Bibliographies from relevant research articles were also reviewed for inclusion.

STUDY SELECTION AND DATA EXTRACTION

All original research articles available in the English language were identified from the data sources. Primary literature evaluating outcomes related to urinary dysfunction and associated symptoms in women were included in this review. Articles describing the use of α-adrenergic blockers in other medical conditions or in men were excluded.

DATA SYNTHESIS

A total of 15 clinical studies were identified and evaluated. Many studies showed an improvement in female lower-urinary-tract symptoms and dysfunction using α-adrenergic blockers. Most studies also reported adverse drug events of α-adrenergic blockers such as dizziness and hypotension. However, limitations of the studies conducted to date include small sample sizes, inconsistent study designs, and short duration of therapy.

CONCLUSIONS

The role of α-adrenergic blockers in the treatment of urinary dysfunction and associated symptoms in women remains unclear. The majority of evidence suggests that these agents may have a place in therapy for female lower-urinary-tract symptoms and/or bladder outlet obstruction; however, data are conflicting. Clinicians should be aware of the potential clinical benefits but also recognize the potential adverse drug effects of α-adrenergic blockers.

The use of primary and secondary doxazosin XL (8 mg) in the treatment of benign prostate hyperplasia: Is there a new approach in the event of alpha-blocker failure?

OBJECTIVE

Lower urinary tract symptoms (LUTS), which are related to benign prostate hyperplasia (BPH), are the most commonly encountered diseases in urological practice. In our study, we compared responses to (doxazosin mesylate extended release tablets) treatment.

MATERIAL AND METHODS

In our study, we included one hundred patients with LUTS who did not receive any medical treatment, and one hundred patients with LUTS who did not respond to alpha-blocker drugs other than doxazosin XL (8 mg). The inclusion criteria for the study were as follows: international prostate symptom score (IPSS)>7, prostate volume >20 cc, Q-max <15 mL/sn, lack of any previous pelvic or prostatic surgery, and /or urethral catheterization.

RESULTS

The mean age of the patients was 62.2±7.9 years. No statistically significant differences were detected between the groups with respect to age, prostate volume, and total prostate-specific antigen (PSA) levels. The duration of the follow-up period was calculated as 3-26 (mean 11) months. Significant differences were detected in post-voiding residual urine, IPSS, quality of life and Qmax between pre- and post-treatment values. Similar decreases in the IPSS scores, and increases in Qmax values were detected in both groups.

CONCLUSION

Doxazosin XL (8 mg) treatment was found to be efficient and reliable in primary patients and in patients with severe LUTS who did not respond to medical treatment. Trial of doxazosin XL (8 mg) therapy, before surgery in patients who respond inadequately to other alpha-blocker drugs is a rational approach.

(-)Doxazosin is a necessary component for the hypotensive effect of (±)doxazosin during long-term administration in conscious rats

AIM

Doxazosin is a racemic mixture of (-)doxazosin and (+)doxazosin that is currently used as an add-on therapy for hypertension. In this study we investigated the contribution of each enantiomer to the hypotensive action of long-term administration of (±)doxazosin in conscious rats.

METHODS

Blood pressure of conscious SD rats was measured using a volume pressure recording system. The rats were orally administered (-)doxazosin, (+)doxazosin, or (±)doxazosin (8 mg·kg(-1)·d(-1)) for 12 weeks. Plasma concentrations of the agents were analyzed with HPLC. The effect of the agents on α1-adrenoceptor was examined in isolated rat caudal artery preparations.

RESULTS

Treatment of conscious rats with a single dose of (±)doxazosin (8 mg/kg) did not affected DBP and MBP, but significantly decreased SBP by 11.9% 4 h after the administration. Long-term treatment of conscious rats with (±)doxazosin significantly decreased SBP, DBP and MBP with a maximal decrease of SBP by 29.3% 8 h after the last administration. The rank order of the hypotensive actions caused by long-term treatment in conscious rats was (±)doxazosin>(+)doxazosin>>(-)doxazosin. However, the pKB values for inhibiting NA-induced contraction of isolated rat caudal artery were (+)doxazosin (8.995)>(±)doxazosin (8.694)>(-)doxazosin (8.032). The plasma concentrations of (-)doxazosin, (+)doxazosin, and (±)doxazosin were 18.26±3.55, 177.11±20.66, and 113.18±13.21 ng/mL, respectively, 8 h after the last administration of these agents.

CONCLUSION

Long-term treatment with (±)doxazosin produces potent hypotensive action in conscious rats that seems to result from synergic interaction of the two enantiomers.

Neurological status predicts response to alpha-blockers in men with voiding dysfunction and Parkinson's disease

OBJECTIVES

To evaluate predictors of the response to doxazosin, a selective alpha-adrenoceptor antagonist, when used for the treatment of lower urinary tract symptoms in men with Parkinson's disease.

METHODS

In a prospective study, 33 consecutive men (mean age 59.2 ± 7.0 years) with Parkinson's disease and lower urinary tract symptoms were evaluated. Neurological dysfunction was assessed with the Unified Parkinson's Disease Rating Scale. Urological assessment was performed at baseline and after 12 weeks of treatment with 4 mg/day of extended-release doxazosin, including symptom evaluation with the International Continence Society male short-form questionnaire, an assessment of the impact of lower urinary tract symptoms on quality of life and urodynamics. Clinical and urodynamic predictors of response were specifically evaluated.

RESULTS

Compared with the score at baseline, the total International Continence Society male short-form score was reduced after doxazosin administration, from 17.4 ± 7.5 to 11.1 ± 6.9 (p<0.001). The impact of lower urinary tract symptoms on quality of life was also significantly reduced, from 1.8 ± 1.1 to 1.0 ± 1.0 (p<0.001) and the maximum urinary flow varied from 9.3 ± 4.4 to 11.2 ± 4.6 ml/s (p=0.025). The severity of neurological impairment was the only predictor of the clinical response. Additionally, patients with a Unified Parkinson's Disease Rating Scale score lower than 70 had a significantly higher chance of clinical improvement with doxazosin treatment than those with higher Unified Parkinson's Disease Rating Scale scores did (RR=3.10, 95% CI=[1.15 to 5.37], p=0.011).

CONCLUSIONS

Doxazosin resulted in the improvement of lower urinary tract symptoms and the maximum flow rate and was well tolerated in men with Parkinson's disease. The response to treatment is dependent on the severity of neurological disability.

Therapeutic value of quinazoline-based compounds in prostate cancer

Certain α1-adrenoreceptor antagonists induce significant apoptosis and impair tumor vascularity without affecting cellular proliferation, effects specific to the quinazoline structure. These anticancer effects have been attributed to both induction of classical apoptosis and reversal of anoikis resistance via disruption of integrin-mediated cell survival pathways. Recent drug optimization efforts have generated several novel compounds with quinazoline-derived chemical structure that exert potent anti-tumor activity via anoikis. Results from pre-clinical and clinical studies implicate a potential value of quinazoline-based analogues in prostate cancer prevention and therapy. A retrospective study of a large patient cohort at our center, revealed that treatment with α1-andrenoreceptor antagonists significantly reduced the risk of developing prostate cancer, indicating a potential chemopreventative mechanism for these FDA-approved agents. In the present review we discuss the current understanding of the signaling mechanisms reversing anoikis resistance by the quinazoline-based compounds in prostate tumors, towards enabling identification of novel therapeutic targets for the treatment of metastatic castration-resistant prostate cancer (CRPC).

In vivo blockade of α1-adrenergic receptors mitigates stress-disturbed cAMP and cGMP signaling in Leydig cells

The molecular mechanism of stress-associated reproductive dysfunction is complex and largely unknown. This study was designed to systematically analyze molecular effects of systemic in vivo blockade of α1-adrenergic receptors (α1-ADRs) on stress-induced disturbance of cAMP/cGMP signaling in testosterone-producing Leydig cells using the following parameters (i) level of circulating stress hormones, LH and testosterone; (ii) level of main molecular markers of Leydig cell functionality (testosterone, Insl3, cAMP); (iii) expression of cAMP signaling (cAMP 'producers'/'effectors'/'removers') and (iv) expression of NO-cGMP signaling (NO-cGMP 'producers'/'effectors'/'removers'). The results showed that oral administration of α1-ADR blocker before stress increased cGMP and diminished stress-reduced cAMP production in Leydig cells. In the same cells, stress-induced effects on cAMP/cGMP signaling pathways elements were changed. Sustained in vivo α1-ADR blockade completely abolished stress-increased transcription of most abundantly expressed phosphodiesterase that remove cAMP (Pde4b) and potentiated stress-increased expression of PRKA, the main stimulator of Leydig cell steroidogenesis. In the same Leydig cells, stress-decreased NOS3 expression was abolished, while stress-increased GUCY1 (cGMP 'producer') and PRKG1 (cGMP 'effector') were potentiated. It is possible that all molecules mentioned could contribute, at least in part, in recovery of Leydig cell testosterone production. Presented data provide new role of α1-ADRs in stress-triggered disturbance of cAMP/cGMP signaling, and new molecular insights into the relationship between stress and mammalian reproduction. Regardless of whether the effects of α1-blocker + stress are direct or indirect, the results are important in terms of human reproductive health and the wide use of α1-ADR antagonists, alone or in combination, to treat post-traumatic stress disorders, hypertension, benign prostatic hyperplasia symptoms and potential drugs for prostate cancer prevention/treatment.

Sustained in vivo blockade of α₁-adrenergic receptors prevented some of stress-triggered effects on steroidogenic machinery in Leydig cells

This study was designed to systematically analyze and evaluate the effects of in vivo blockade of α₁-adrenergic receptors (α₁-ADRs) on the stress-induced disturbance of steroidogenic machinery in Leydig cells. Parameters followed 1) steroidogenic enzymes/proteins, transcription factors, and cAMP/testosterone production; 2) the main hallmarks of stress (epinephrine, glucocorticoids); and 3) transcription profiles of ADRs and oxidases with high affinity to inactivate glucocorticoids. Results showed that sustained blockade of α₁-ADRs prevented stress-induced 1) decrease of the transcripts/proteins for main steroidogenic CYPs (CYP11A1, CYP17A1); 2) decrease of Scarb1 and Hsd3b1 transcripts; 3) decrease of transcript for Nur77, one of the main activator of the steroidogenic expression; and 4) increase of Dax1 and Arr19, the main steroidogenic repressors in Leydig cells. In the same cells, the expression of steroidogenic stimulatory factor Creb1, StAR, and androgen receptor increased. In this signaling scenario, stress-induced stimulation of Adra1a/Adra1b/Adrbk1 and Hsd11b2 (the unidirectional oxidase with high affinity to inactivate glucocorticoids) was not changed. Blockade additionally stimulated stress-increased transcription of the most abundantly expressed ADRs Adra1d/Adrb1/Adrb2 in Leydig cells. In the same cells, stress-decreased testosterone production, the main marker of Leydig cells functionality, was completely prevented, while reduction of cAMP, the main regulator of androgenesis, was partially prevented. Accordingly, the presented data provide a new molecular/transcriptional base for "fight/adaptation" of steroidogenic cells and new molecular insights into the role of α₁-ADRs in stress-impaired Leydig cell steroidogenesis. The results are important in term of wide use of α₁-ADR selective antagonists, alone/in combination, to treat high blood pressure, nightmares associated with posttraumatic stress disorder, and disrupted sexual health.

The alpha-1 adrenergic antagonist doxazosin for treatment of cocaine dependence: A pilot study

BACKGROUND

Medications decreasing central noradrenergic activity have been associated with attenuation of cocaine effects.

AIMS

This pilot study examined the efficacy of doxazosin versus placebo for reducing cocaine use in treatment-seeking cocaine dependent persons.

METHODS

We screened 108 cocaine dependent subjects and assigned 35 participants to receive either doxazosin (8mg/day) or placebo for 13 weeks. Participants were titrated on the study medication according to two different schedules. During the initial phase of the study, patients were titrated onto the study medication over an 8-week period (DOX-slow). After reviewing data from our human laboratory study, a second phase was initiated, wherein titration was accelerated to a 4-week period (DOX-fast). All participants received weekly cognitive behavioral therapy. Urine toxicology was performed thrice weekly.

RESULTS

Baseline subject characteristics were comparable. Thirty subjects entered the study: 8 subjects in DOX-slow, 9 subjects in DOX-fast, and 13 subjects in placebo. Total number of cocaine-negative urines was significantly increased in the DOX-fast group; and percentage of total cocaine-negative urines by group were 10% for DOX-slow group, 35% for DOX-fast group, and 14% for placebo (χ(2)=36.3, df=2, p<0.0001). The percentage of participants achieving two or more consecutive weeks of abstinence by group was 0% for DOX-slow group, 44% for DOX-fast group, and 7% for placebo (χ(2)=7.35, df=2, p<0.023).

CONCLUSIONS

This pilot study suggests the potential efficacy of doxazosin when rapidly titrated in reducing cocaine use.

Prostate epithelial stem cells are resistant to apoptosis after α1-antagonist treatment. The impact for BPH patients

INTRODUCTION

Induction of apoptosis in prostatic epithelial cells by doxazosin, terazosin and prazosin has been well documented. However, the biochemical pathways of doxazosin action is still unclear. Aforementioned drugs should lead to decrease of prostate volume, although this effect was never observed in patients suffering from BPH after treatment with α1-antagonists. Probably, it is connected with cancer stem cells' resistance on chemotherapeutic agents. The aim of this study was to compare incidence of apoptosis induced by doxazosin in progenitor and differentiated cells isolated from human prostate epithelium.

MATERIAL AND METHODS

For this purpose tissue specimens were obtained from 10 patients suffering from BPH, the primary cultures of prostate epithelium were established and CD133 MicroBeads sorting was prepared. Both, CD133(+)/CD133(-) co-cultures and CD133(+) cells were incubated with different concentration of doxazosin for 12 h. Cell viability and apoptosis was estimated with Annexin V-FITC.

RESULTS

12 h incubation of CD133(+)/CD133(-) co-cultures with doxazosin resulted in increase of apoptotic cells, while in CD133(+) cultures no changes were observed. Correlation between apoptotic cell number and doxazosin concentration in CD133(+)/ CD133(-) co-cultures group was high (R = 0.99).

CONCLUSION

Doxazosin induced apoptosis in co-cultures of progenitor and differentiated epithelial cells. However, progenitor cells were not susceptible to apoptosis, what can be a reason of treatment failure in BPH patients.