Tamsulosin: a review of its pharmacology and therapeutic efficacy in the management of lower urinary tract symptoms

Effect of dapoxetine on the pharmacokinetics and hemodynamic effects of tamsulosin in men on a stable dose of tamsulosin

The tolerability of dapoxetine, a short-acting selective serotonin reuptake inhibitor being developed for premature ejaculation, was evaluated when coadministered with tamsulosin. Adult men on a stable dose of tamsulosin were randomized to also receive dapoxetine 30 or 60 mg, or placebo, in a crossover design. Supine and standing vital signs were measured on days 1 and 7. Plasma samples were collected for measurement of tamsulosin, dapoxetine, and dapoxetine metabolites. Coadministration of dapoxetine with tamsulosin did not alter orthostatic profiles or affect the incidence of orthostatic hypotension. Tamsulosin and dapoxetine pharmacokinetics were not altered. Adverse events were reported by 5.4%, 10.9%, and 23.2% of participants receiving tamsulosin with placebo, dapoxetine 30 mg, and dapoxetine 60 mg, respectively. The most common adverse events were diarrhea, dizziness, headache, and nausea. Therefore, dapoxetine had no clinically important effects on the pharmacokinetics or orthostatic profile of tamsulosin in men on a stable tamsulosin regimen.

Tadalafil administered once daily for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a dose finding study

PURPOSE

Phosphodiesterase type 5 inhibitors are widely used to treat erectile dysfunction. Preliminary data have suggested phosphodiesterase type 5 inhibitor efficacy in men with lower urinary tract symptoms associated with clinical benign prostatic hyperplasia.

MATERIALS AND METHODS

After a 4-week placebo run-in period 1,058 men with benign prostatic hyperplasia lower urinary tract symptoms were randomly allocated to receive 12-week, once daily treatment with placebo or tadalafil (2.5, 5, 10 or 20 mg).

RESULTS

The International Prostate Symptom Score least squares mean change from baseline to end point was significantly improved for 2.5 (-3.9, p = 0.015), 5 (-4.9, p <0.001), 10 (-5.2, p <0.001) and 20 mg (-5.2, p <0.001) tadalafil compared to placebo (-2.3). International Prostate Symptom Score improvements at 4, 8 and 12 weeks were significant for all tadalafil doses and they demonstrated a dose-response relationship. Tadalafil (2.5 mg) significantly improved the International Prostate Symptom Score obstructive subscore and the International Index of Erectile Function-Erectile Function domain, the latter in sexually active men with a history of erectile dysfunction. Statistically significant improvements were noted for 5, 10 and 20 mg tadalafil compared to placebo, as assessed by the International Prostate Symptom Score irritative and obstructive subscores, International Prostate Symptom Score Quality of Life, Benign Prostatic Hyperplasia Impact Index (nonsignificant for 10 mg), Global Assessment Question and International Index of Erectile Function-Erectile Function domain. No statistically significant effect of treatment compared to placebo was noted for peak flow at any tadalafil dose. Treatment emergent adverse events were infrequent in all tadalafil groups.

CONCLUSIONS

Once daily tadalafil demonstrated clinically meaningful and statistically significant efficacy and it was well tolerated in men with benign prostatic hyperplasia lower urinary tract symptoms. Of the doses studied 5 mg tadalafil appeared to provide a positive risk-benefit profile.

Clinical experience with intraoperative floppy-iris syndrome. Results of the 2008 ASCRS member survey

According to an online survey, most members of the American Society of Cataract and Refractive Surgery believe that tamsulosin makes cataract surgery more difficult (95%) and increases the risks of surgery (77%). Commonly reported complications of intraoperative floppy-iris syndrome (IFIS) were significant iris trauma and posterior capsule rupture, with 52% and 23% of respondents, respectively, reporting these complications at a higher rate than in non-IFIS eyes. There was no single preferred surgical method for managing IFIS; 33% of respondents routinely used multiple strategies. Of respondents with sufficient experience, 90% believe that IFIS is more likely with tamsulosin than with nonspecific alpha1-antagonists. Ninety-one percent believe that physicians prescribing alpha1-antagonists should become better educated about IFIS, and 59% would recommend a pretreatment ophthalmic evaluation for patients with cataracts or decreased vision. If they themselves had mildly symptomatic cataracts, 64% of respondents would avoid taking tamsulosin or would have their cataract removed first.

Tamsulosin modified release and oral controlled absorption system in the management of lower urinary tract symptoms suggestive of benign prostatic hyperplasia

BACKGROUND

Tamsulosin MR has been on the market for the treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) for many years. Recently, tamsulosin OCAS was introduced, which has improved pharmacokinetics.

OBJECTIVE

To evaluate the efficacy and safety of tamsulosin.

METHODS

Literature was identified through a PubMed search using the term 'tamsulosin' and by screening reference lists of review articles.

RESULTS

Tamsulosin rapidly improves LUTS/BPH, with benefits maintained in the long-term. The overall tolerability of tamsulosin MR 0.4 mg is comparable to that of placebo. While the efficacy of tamsulosin OCAS and MR is comparable, tamsulosin OCAS is slightly better tolerated.

CONCLUSION

Tamsulosin OCAS 0.4 mg has a favourable efficacy/safety profile and should be considered the treatment of choice for patients requiring optimal symptom control without increasing the risk of cardiovascular adverse events.

Pharmacological management of renal colic in the older patient

Renal colic affects up to 12% of the population. Initial management of most patients is expectant. Acute symptom management of renal colic is best accomplished with a combination of parenteral opioids and NSAIDs. The elderly patient with a kidney stone should be screened for contraindications to NSAID therapy, such as renal failure or previous peptic ulcer disease. Use of parenteral opioids is often necessary during the acute setting, and downward-adjusted doses and monitoring are necessary to prevent associated confusion and respiratory depression. Novel therapy with desmopressin may also be effective for symptom control at the initial presentation, without the adverse effects of opioids or NSAIDs. However, use of desmopressin in the elderly must be undertaken cautiously, given the potential adverse effects of this agent. Many small, distal ureteral stones are treated initially with watchful waiting for the first 2-4 weeks after presentation. The patient should have effective, non-parenteral analgesics for use at home. Included in these agents are oral or suppository NSAIDs and oral opioids. Medical expulsion therapy with alpha-adrenoceptor antagonists or calcium channel antagonists is efficacious. alpha-Adrenoceptor antagonists such as the alpha(1A/)(1)(D)-selective tamsulosin are well tolerated in the elderly and increase the rate of spontaneous stone passage by approximately 50% for small distal stones. These agents also appear to decrease the severity of renal colic. Corticosteroids and calcium channel antagonists are also effective but their use in the elderly is not recommended as first-line therapy.

Prospective Multicenter Evaluation of Cataract Surgery in Patients Taking Tamsulosin (Flomax)

PURPOSE

Intraoperative floppy iris syndrome (IFIS) caused by systemic alpha-blockers has been associated with an increased risk of cataract surgical complications when the surgeon was unaware of the medication history and did not anticipate its occurrence. This study was undertaken to evaluate the surgical outcomes and rate of complications when the ophthalmologist knew the patient was taking tamsulosin (Flomax, Boehringer-Ingelheim Pharmaceuticals, Ridgefield, CT) and used 1 of several strategies to manage IFIS.

DESIGN

Prospective multicenter nonrandomized observational series.

PARTICIPANTS

A total of 167 consecutive eyes in 135 patients taking tamsulosin and undergoing cataract surgery.

METHODS

Phacoemulsification was performed in conjunction with at least 1 of 4 different IFIS management strategies, namely, topical atropine preoperatively, iris retractors, pupil expansion ring, or use of viscoadaptive ophthalmic viscosurgical device with reduced fluidic parameters.

MAIN OUTCOME MEASURES

Severity of IFIS, incidence of operative or postoperative complications, and final visual acuity.

RESULTS

The IFIS severity was rated as mild in 17%, moderate in 30%, and severe in 43% of the study eyes. No IFIS was noted in 10% of the eyes. The rate of posterior capsule rupture and vitreous loss was 0.6% (1/167; 95% confidence interval, 0%-1.8%). Ninety-five percent of eyes achieved a best-corrected visual acuity of at least 20/40.

CONCLUSION

When experienced surgeons could anticipate IFIS and employ compensatory surgical techniques, the complication rate from cataract surgery was low and the visual outcomes were excellent in eyes of patients with a history of tamsulosin use.

Epigenetic regulation of human alpha1d-adrenergic receptor gene expression: a role for DNA methylation in Sp1-dependent regulation

A growing body of evidence implicates alpha1-adrenergic receptors (alpha1ARs) as potent regulators of growth pathways. The three alpha1AR subtypes (alpha1aAR, alpha1bAR, alpha1dAR) display highly restricted tissue expression that undergoes subtype switching with many pathological stimuli, the mechanistic basis of which remains unknown. To gain insight into transcriptional pathways governing cell-specific regulation of the human alpha1dAR subtype, we cloned and characterized the alpha1dAR promoter region in two human cellular models that display disparate levels of endogenous alpha1dAR expression (SK-N-MC and DU145). Results reveal that alpha1dAR basal expression is regulated by Sp1-dependent binding of two promoter-proximal GC boxes, the mutation of which attenuates alpha1dAR promoter activity 10-fold. Mechanistically, chromatin immunoprecipitation data demonstrate that Sp1 binding correlates with expression of the endogenous gene in vivo, correlating highly with alpha1dAR promoter methylation-dependent silencing of both episomally expressed reporter constructs and the endogenous gene. Further, analysis of methylation status of proximal GC boxes using sodium bisulfite sequencing reveals differential methylation of proximal GC boxes in the two cell lines examined. Together, the data support a mechanism of methylation-dependent disruption of Sp1 binding in a cell-specific manner resulting in repression of basal alpha1dAR expression.

Floppy iris behaviour during cataract surgery: associations and variations

AIM

To assess the association of floppy iris behaviour during cataract surgery with use of alpha-1-antagonists and diabetes mellitus.

METHODS

1842 eyes of 1786 patients undergoing phacohoemulsification surgery were prospectively enrolled. The use of commonly prescribed alpha-1-antagonists and the presence or absence of diabetes mellitus were noted. The occurrence of any of the features of the intraoperative floppy iris syndrome (IFIS) was noted by surgeons blinded to the patient's history.

RESULTS

57% of patients receiving tamsulosin showed features of IFIS compared with 1% of the non-tamsulosin group (p<0.001). Of these, more than half the patients manifested the syndrome in an incomplete form. Only 1 of the 51 patients receiving other alpha-1-antagonists had IFIS. Diabetes was also not associated with IFIS (p = 1).

CONCLUSIONS

Tamsulosin is significantly associated with floppy iris behaviour during cataract surgery. But not all of these patients will necessarily show all or any features of IFIS. The floppy iris syndrome is likely to represent a continuum of severity. Various undefined factors, diabetes not being one of them, may have a contributory role. Non-selective alpha-1-antagonists are unlikely to be associated with IFIS.

Determination of tamsulosin in human aqueous humor and serum by liquid chromatography–electrospray ionization tandem mass spectrometry

A simple, sensitive and selective LC-MS/MS method was developed for the determination of tamsulosin in human aqueous humor and serum to study the recently reported eye-related adverse effects of this alpha(1)-blocker drug. Aqueous humor samples were analyzed by direct injection, after addition of the internal standard, labetalol. Liquid-liquid extraction with ethyl acetate was used for serum sample preparation. The chromatographic separation was performed on a reversed phase column by gradient elution with acetonitrile -0.1% formic acid at a flow-rate of 0.2 ml/min. Detection and quantification of the analytes were carried out with a linear ion trap mass spectrometer, using positive electrospray ionization (ESI) and multiple reaction monitoring (MRM). The limit of quantification was 0.1 ng/ml for both aqueous humor and serum samples and linearity was obtained over the concentration ranges of 0.1-4.7 ng/ml and 0.1-19.3 ng/ml for aqueous humor and serum samples, respectively. Acceptable accuracy and precision were obtained for concentrations within the standard curve ranges. The method has been used for the determination of tamsulosin in aqueous humor and serum samples from patients that were on tamsulosin medication and underwent cataract surgery.

Public, patient, and professional attitudes towards the diagnosis and treatment of enlarged prostate: A landmark national US survey

This US national survey evaluated beliefs and attitudes towards the enlarged prostate (EP) and its treatment among the men of a national sample aged > or =50 years in the US (400 with and 700 without EP), and a national sample of 100 primary care doctors and 100 urologists. The principal risk of EP was considered to be acute urinary retention among the majority of physicians, while the majority of patients believed it to be prostate cancer. In contrast to physicians' beliefs, the majority of patients with moderate-to-severe symptoms are more concerned with long-term effects of EP than acute symptoms. Furthermore, they are willing to wait up to 3 months for symptom relief if treatment of the underlying condition is achieved. Doctors and patients agree that most patients want to avoid surgery but only 18% of surgery patients were told about drugs that could reduce the risk of surgery. These findings demonstrate significant differences between the beliefs and attitudes of patients and physicians towards EP.

Effects of chronic administration of doxazosin on alpha1-adrenoceptors in the rat prostate

PURPOSE

Although the clinical efficacy of alpha1-adrenoceptor (alpha1-AR) antagonists for the treatment of benign prostatic hyperplasia is not disputed, their mechanism of action and ability to maintain long-term effectiveness have only recently been investigated. Since it is known that chronic administration of receptor antagonists causes up-regulation in the targeted receptor, we examined the effects of chronic administration of doxazosin, a nonspecific long acting alpha1-AR antagonist, on the properties of alpha1-AR subtypes in the rat prostate.

MATERIALS AND METHODS

Rats were treated with doxazosin (2 or 4 mg/kg daily subcutaneously, supplemented with 4 mg/kg daily orally) for 8 or 12 weeks. Prostatic alpha1-AR properties at the protein and gene transcript levels were quantified by radioligand receptor binding and real-time reverse transcriptase-polymerase chain reaction, respectively.

RESULTS

Treated rats that received the highest levels of doxazosin had significantly heavier prostates compared with age matched controls. After 12 weeks of treatment radioligand binding studies with radiolabeled alpha1-AR antagonist demonstrated no significant differences in the density of total alpha1-ARs in the prostate, whereas the results of real-time reverse transcriptase-polymerase chain reaction showed up-regulation in the mRNA expression levels of all 3 alpha1-AR subtypes (alpha1A, alpha1B and alpha1D) in the ventral and dorsolateral regions of the rat prostate.

CONCLUSIONS

These data demonstrate that chronic treatment with doxazosin causes an alteration in the properties of the alpha1-AR system in the rat prostate. These findings may provide insight into the long-term effectiveness of alpha1-AR antagonists in the treatment of benign prostatic hyperplasia.

Safety and efficacy of tamsulosin in the treatment of painful ejaculation: a randomized, double-blind, placebo-controlled study

We evaluate the efficacy and safety of tamsulosin a selective alpha(1A)-receptor antagonist in patients with painful ejaculation (PE) as a sole entity. A total of 118 men with PE were included in the study. Patients were randomly assigned to receive 0.4 mg oral daily tamsulosin (group 1, n=59) or placebo (group 2, n=59), during a 6-week period for each agent. Pretreatment evaluation included history and physical examination, International Index of Erectile Function (IIEF) and a visual analog scale (VAS) for pain. The efficacy of two treatments was assessed every 2 weeks during treatment, and at the end of the study using responses to IIEF, VAS evaluation, mean intercourse satisfaction domain, mean weekly coitus episodes and adverse drug effects. In all, 104 patients (88%) completed the whole treatment schedule. Pain resolved in 16 and 13% of the patients treated with tamsulosin and placebo, respectively (P=0.1). Baseline mean intercourse satisfaction domain values of IIEF 10 and 11 reached to 12 and 10 at 6-week treatment in groups 1 and 2, respectively (P=0.08). The VAS after tamsulosin and placebo decreased from 5.7 and 5.8 to 5.1 and 5.5, respectively (P=0.1). The mean weekly intercourse episodes increased from pretreatment values of 1.8 and 1.6 to 1.9 and 1.7, for tamsulosin and placebo, respectively (P=0.08). Mean number of adverse events was 11 for tamsulosin and 5 for placebo (P<0.05). Tamsulosin is no better than placebo in improvement of PE as a sole entity.

Comparison of the Cardiovascular Effects of Tamsulosin Oral Controlled Absorption System (OCAS®) and Alfuzosin Prolonged Release (XL)

OBJECTIVE

The cardiovascular (CV) effects of tamsulosin oral controlled absorption system (OCAS) 0.4 mg were compared with those of alfuzosin prolonged release (XL) 10 mg.

METHODS

Two single-dose, crossover studies were performed. In study 1, CV alpha1-adrenoceptor antagonism was assessed by measuring the inhibition of phenylephrine (PE)-induced increases in diastolic blood pressure (DBP) and total peripheral resistance (TPR) before and after dosing with placebo, tamsulosin OCAS, and alfuzosin XL in 18 young subjects. In study 2, orthostatic stress tests (OTs) were performed before and after dosing with tamsulosin OCAS and alfuzosin XL in 40 elderly subjects. Pharmacokinetics were assessed in both studies.

RESULTS

In study 1, tamsulosin OCAS induced statistically significantly less inhibition of PE-induced increases in DBP at 2 h after dosing and in TPR at 2 and 4 h after dosing than alfuzosin XL. In study 2, tamsulosin OCAS had a lower incidence of positive OTs than did alfuzosin XL, with the difference between both treatments being statistically significant at 6h after dosing and for all time points after dosing combined. This was in line with smaller changes in vital signs observed for tamsulosin OCAS. The t(max) values for both treatments were comparable.

CONCLUSIONS

Tamsulosin OCAS 0.4 mg produces smaller vascular effects than does alfuzosin XL 10 mg.

Alpha-adrenoceptors are a common denominator in the pathophysiology of erectile function and BPH/LUTS - implications for clinical practice

A literature search of PubMed documented publications and abstracts from proceedings of scientific meetings was made to review the available data on benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) and erectile dysfunction (ED) with a special focus on the role of alpha-adrenoceptors as critical mediators of pathophysiology. The reader is introduced to clinical results on the therapeutic potential of alpha-blockers alone and in combination with phosphodiesterase type 5 (PDE-5) inhibitors in the treatment of ED associated with LUTS/BPH. Epidemiological studies clearly show that an association exists between ED and LUTS/BPH. The severity of LUTS is correlated with the risk for ED. A significant number of LUTS/BPH patients are nonresponsive to the common ED treatment with PDE-5 inhibitors. As smooth muscle contractility is regulated by adrenoceptors in the corpus cavernosum, prostate and detrusor, the alpha-adrenoceptor system may be considered a common pathophysiological mediator in the development of ED and LUTS/BPH. Blockade of alpha-adrenoceptors for the treatment of BPH/LUTS may have the potential of improving sexual function. Conversely, PDE-5 inhibitors may exhibit positive effects in LUTS patients. Pilot studies on combination regimens of alpha-adrenoceptor antagonists and PDE-5 inhibitors have yielded encouraging results in LUTS patients with persistent ED. On the basis of pharmacological and clinical evidence, it is established that the alpha-adrenoceptor system plays an important role in the pathophysiology of ED and LUTS secondary to BPH. Larger trials on the combination of alpha-adrenoceptor antagonists with PDE-5 inhibitors are necessary to develop an integrated treatment approach for BPH/LUTS patients with comorbid ED.

Recovery of Abnormal Ejaculation by Intermittent Tamsulosin Treatment

PURPOSE

We assessed the impact of intermittent tamsulosin treatment on abnormal ejaculation.

MATERIALS AND METHODS

This prospective study was performed between January 2001 and December 2004. It included 405 patients who were at least 50 years old with lower urinary tract symptoms. This study was divided into 2 phases. In phase 1 patients received a 0.4 mg tamsulosin capsule daily after breakfast for at least 3 months. The second phase of this study was performed in the 30 patients with abnormal ejaculation. In this phase these patients received 0.4 mg tamsulosin once daily every other day. Patients were assessed at study entry and at study week 6.

RESULTS

Abnormal ejaculation was reported as retrograde ejaculation by 18 patients, as decreased volume by 7 and as absent ejaculate by 5. Ejaculatory function recovered during intermittent tamsulosin treatment in 12 patients with retrograde ejaculation and in 7 with decreased volume or absent ejaculate. As a result, 19 of 30 patients (63.3%) with abnormal ejaculation recovered. A significant improvement in retrograde ejaculation was found after intermittent tamsulosin treatment (p = 0.02). Although there were improvements in decreased volume or absent ejaculate at week 6 of intermittent treatment, these differences were not statistically significant (p = 0.42 and 0.61, respectively).

CONCLUSIONS

The results of the current study, which to our knowledge is the first report of the effect of intermittent tamsulosin treatment on abnormal ejaculation, show that this treatment modality is well tolerated and provides comparable improvements for abnormal ejaculation.

The use of tamsulosin in the medical treatment of ureteral calculi: where do we stand?

It has recently been demonstrated that specific adrenoceptors subtypes (alpha(1A)/alpha(1D)) are prevalent in the distal part of the ureter, a finding supporting the interesting results obtained by different groups with the use of tamsulosin in the treatment of distal ureteral calculi. We performed a prospective randomized study to evaluate the effects of the addition of tamsulosin on our standard pharmacological therapy for the treatment of selected ureteral stones. A total of 64 patients referred to our department for the management of symptomatic ureteral calculi were considered. Patients were randomly divided into two treatment groups: group A (n=32) who received diclofenac (100 mg/daily) plus aescin (80 mg/daily) and group B (n=32) who received the same therapy plus tamsulosin (0.4 mg/daily) for a maximum of 2 weeks. No significant differences were found between the groups for age, gender distribution and mean stone size measured in the single largest dimension at presentation. The stone expulsion rate was 60% (19/32 patients) for group A and 88% for (28/32) for group B with a mean expulsion time of 7.4+/-2.2 (range 3.5-12) and 4.8+/-2.7 days (range 1.8-10.5), respectively. Group B showed a significant advantage in terms of both expulsion rate (P=0.01) and expulsion time (P=0.005). Different analgesics from those used in the standard treatment regimen were required in ten patients in group A (31%) but only three patients in group B (9%). This difference was significant (P=0.003). Hospitalization for recurrent colic was needed in 21% of patients in group A (7/32) and in 9% in group B (3/32) (P=0.01). Only two patients in each group (6%) experienced minor side effects associated with the expulsive therapy. Our data confirm the efficacy of tamsulosin in the treatment of distal ureteral stones up to 1 cm. This selective alpha-blocker should therefore be included in the pharmacological regimen of patients when a conservative approach is considered in the treatment of ureteral lithiasis.

The effects of alpha1A-adrenoceptor antagonists on the urethral perfusion pressure of the female rat

OBJECTIVE

To assess the effects of alpha(1A)-adrenoceptor antagonists on urethral perfusion pressure (UPP) in the female rate and their therapeutic potential for treating female bladder outlet obstruction (BOO).

MATERIALS AND METHODS

A cannula was inserted into the femoral arteries of female rats to administer tamsulosin (group I), doxazosin (group II) or phentolamine (group III) and to monitor systemic blood pressure. Tamsulosin was also administered to male rats (group IV). UPP and vesical pressures (Pves) were monitored using a triple-lumen catheter.

RESULTS

After administration of tamsulosin to group I the frequency of bladder contractions decreased significantly and the duration of minimal urethral relaxation with high-frequency oscillations (HFOs) was significantly prolonged. Except for mean arterial blood pressure (MAP), none of the variables in group I differed significantly from those in group II and group III. The change in MAP after tamsulosin treatment was significantly lower than after doxazosin or phentolamine. Except for the maximum Pves, which was significantly higher in males (group IV) than in females of group I, the UPP and Pves curves of male rats were similar to those of females before giving tamsulosin. The prolonged frequency and duration of HFO in group IV (with tamsulosin) were significantly different from those of females.

CONCLUSIONS

The alpha(1A)-adrenergic receptor may be a functional subtype in the female rat urethra. alpha(1A)-adrenoceptor antagonists prolonged the duration of HFOs and decreased the frequency of involuntary bladder contraction. It is possible that treatment with alpha(1A)-adrenoceptor antagonists would not only improve obstructive symptoms, but also ameliorate irritative symptoms by prolonging HFOs and the frequency of involuntary bladder contractions.

Selecting therapy for maintaining sexual function in patients with benign prostatic hyperplasia

In the first of these mini-reviews the selection of therapy for the maintenance of sexual function in patients with BPH is outlined, along with an explanation of how altered regulation of neurotransmitters, especially noradrenaline, may underlie the syndrome of LUTS and sexual dysfunction. Other mini-reviews outline the current status of robotic surgery to treat renal and adrenal disorders, and its future applications, and the potential use of the nitric oxide/cGMP pathway as a potential target to treat BOO associated with benign prostatic enlargement. Finally, the capacity to be creative in academic departments is extolled as a core property of academicians, and its surfacing described as having the potential to revitalize individuals and departments.

Doxazosin-induced up-regulation of alpha 1A-adrenoceptor mRNA in the rat lower urinary tract

Alpha1-adrenoceptor (AR) antagonists can provide effective treatment of symptoms caused by benign prostatic hyperplasia. However, their mechanisms of action have not been fully elucidated. We previously reported that chronic administration of doxazosin causes an up-regulation in the mRNA expression of all three alpha1-AR subtypes in the rat prostate. As alpha1-AR antagonists might also affect the properties of alpha1-ARs in the lower urinary tract, we examined the effects of doxazosin (2 or 4 mg/kg daily subcutaneously, supplemented with 4 mg/kg daily orally for 8 or 12 weeks) on alpha1-AR subtype mRNAs in the rat bladder dome, bladder base, and urethra using real-time reverse transcription PCR. Rats that received the highest doses of doxazosin had significantly heavier bladder base and prostatic urethra than controls. PCR data showed that all three alpha1-AR subtypes were expressed in all tissues studied. Doxazosin treatment caused an up-regulation in the mRNA levels of alpha1A-AR in the rat bladder base and prostatic urethra, indicating that chronic doxazosin treatment may cause an alteration in the properties of alpha1A-AR subtype mRNA in these two areas. Furthermore, the heavier bladder base and prostatic urethra in the doxazosin-treated rats suggest that alpha1-AR antagonist treatment might also influence the growth process in these areas of the rat lower urinary tract.

Intraoperative floppy iris syndrome associated with tamsulosin

PURPOSE

To assess the incidence and possible causative factors of a newly recognized syndrome, the intraoperative floppy iris (IFIS).

SETTING

Clinical practices in Los Altos and San Rafael, California, USA.

METHODS

A retrospective chart review of consecutive cataract surgeries performed in a 2-surgeon practice over a 12-month period (706 eyes; 511 patients) was used to assess the percentage of cataract patients on systemic sympathetic alpha-1 antagonist medications as well as the percentage of patients who manifested the IFIS. A separate prospective study of 900 consecutive cases (741 patients) performed by another surgeon was used to determine the incidence of IFIS and the percentage of these patients who were taking alpha-1 antagonist medications.

RESULTS

Three percent (16/511) of the patients in the retrospective study, representing 3.0% (25/706) of the total eyes, were taking tamsulosin (Flomax) for benign prostatic hypertrophy. The overall prevalence of IFIS was 2.0% (10/511 patients). The syndrome was noted intraoperatively in 63.0% (10/16) of the tamsulosin patients but in none of the 11 patients on other systemic alpha-1 blockers. In the prospective study of 900 consecutive cataract surgeries, the prevalence of IFIS was 2.2% (16/741 patients). Ninety-four percent (15/16) of the IFIS patients were taking or had taken systemic tamsulosin. Twenty-six patients (36 eyes) in the 2 studies had IFIS associated with systemic tamsulosin. Sphincterotomies and mechanical pupil stretching were ineffective in maintaining adequate pupil dilation in this surgical population.

CONCLUSION

Intraoperative floppy iris syndrome occurred in approximately 2% of a cataract surgery population and appeared to be caused by tamsulosin, a systemic sympathetic alpha-1A antagonist medication that is the most frequently prescribed medication for benign prostatic hypertrophy.

Molecular classification of doxazosin-induced alterations in the rat prostate using gene expression profiling

We investigated molecular changes that occurred during chronic administration of doxazosin, an alpha1-adrenoceptor (AR) antagonist, using Affymetrix GeneChip analysis of gene expression. Rats were treated with doxazosin (4 mg/kg/day subcutaneously, supplemented with 4 mg/kg/day orally) for 12 weeks. Labeled cRNA was prepared and the subsequent hybridization to rat 230A arrays was performed. The alterations in gene expression levels of candidate genes identified by microarray analysis with potential biological relevance were verified by real-time reverse transcription polymerase chain reaction (RT-PCR) using SYBR Green I. Doxazosin treated rats had significantly heavier prostates compared to control rats. Microarray analysis revealed that chronic doxazosin treatment caused changes in the expression levels of 625 genes, of which 39 were related to cell death, necrosis, growth, proliferation and G-protein signalling pathways in the rat prostate. Furthermore, RT-PCR experiments, in accord with the microarray analysis, indicated that chronic doxazosin treatment caused an up-regulation in the mRNA expression level of clusterin, an antiapoptotic mediator, and epiregulin, a mitogen, in the ventral and dorsolateral prostate, respectively. These findings, that demonstrate chronic doxazosin administration causes significant changes in the expression of several hundred genes in the rat prostate, may provide insight into the long-term efficacy of alpha1-AR antagonists in the treatment of benign prostatic hyperplasia.

The effect of tamsulosin on the response of the rabbit bladder to partial outlet obstruction

AIM

To determine if tamsulosin treatment prevents or decreases the incidence and severity of outlet obstruction-induced bladder dysfunction in rabbits.

MATERIALS AND METHODS

Male New Zealand White rabbits were treated with tamsulosin or vehicle for 4 weeks with treatments initiated 1 week prior to sham or obstruction surgery. Cystometry was done on anesthetized rabbits 21 days after surgery. The bladders were then removed, weighed, and prepared for in vitro whole bladder studies. Responses to 32 Hz field stimulation (FS), carbachol, phenylephrine, and KCl were measured.

RESULTS

Obstruction resulted in a significant increase in bladder weight, which was unchanged by tamsulosin treatment and a significant increase in micturition pressure in the vehicle-treated group but not in the tamsulosin-treated group. Compliance was significantly decreased in both obstructed groups. The vehicle-treated obstructed rabbits had a very sharp increase in intravesical pressure as the bladder reached capacity; this was not seen in the tamsulosin-treated obstructed rabbits. Tamsulosin did not change the pattern of modifications in contractile responses induced by bladder outlet obstruction.

CONCLUSIONS

In vitro responses of vehicle and tamsulosin-treated obstructed rabbit groups in this study were similar. A greater micturition pressure was found for the vehicle-treated obstructed group than for the tamsulosin-treated obstructed group, which was probably due to decreased urethral resistance in the latter. On a functional basis, the higher compliance at capacity and decreased micturition pressure in the tamsulosin-treated obstructed group would be considered beneficial for bladder function.

INTERACTION BETWEEN THE PHOSPHODIESTERASE 5 INHIBITOR, TADALAFIL AND 2 α-BLOCKERS, DOXAZOSIN AND TAMSULOSIN IN HEALTHY NORMOTENSIVE MEN

PURPOSE

Tadalafil, a phosphodiesterase type 5 inhibitor, is effective therapy for erectile dysfunction (ED). Men with ED have a high incidence of comorbid conditions including cardiovascular disease, diabetes mellitus and benign prostatic hyperplasia. Although phosphodiesterase type 5 inhibitors are safe when administered with most medications, sildenafil given with doxazosin and vardenafil given with terazosin evoke orthostatic hypotension in some patients. We examined the hemodynamic interactions of tadalafil with the alpha-blockers doxazosin and tamsulosin.

MATERIALS AND METHODS

In separate double-blind, placebo controlled, randomized crossover studies (18 patients in each study) we evaluated the hemodynamic effects of doxazosin 8 mg with tadalafil 20 mg, and tamsulosin 0.4 mg with tadalafil 10 and 20 mg. Blood pressure (BP) and heart rate were recorded before dosing and for 24 hours after dosing.

RESULTS

Tadalafil 20 mg augmented the hypotensive effect of doxazosin by producing a mean maximal decrease in standing systolic BP (SBP) that was significantly greater than placebo (a mean difference of 9.8 mm Hg). Analysis of BP outliers showed that the number of subjects with a standing SBP of less than 85 mm Hg was greater after doxazosin plus tadalafil (28%) versus doxazosin plus placebo (6%). In subjects on tamsulosin, tadalafil 10 and 20 mg produced mean maximal decreases in standing SBP that were similar to placebo (mean difference of 1.7 and 2.3 mm Hg, respectively). No subject taking tamsulosin had a decrease in standing SBP less than 85 mm Hg.

CONCLUSIONS

Tadalafil augmented the hypotensive effects of doxazosin but had little hemodynamic interaction with tamsulosin. In patients taking tadalafil for ED, tamsulosin 0.4 mg may be given for the treatment of benign prostatic hyperplasia.

Combination treatment with an alpha-blocker plus an anticholinergic for bladder outlet obstruction: a prospective, randomized, controlled study

PURPOSE

We evaluate the effect of tolterodine combined with tamsulosin on quality of life in patients with bladder outlet obstruction and concomitant detrusor instability.

MATERIALS AND METHODS

The study included 50 consecutive patients with urodynamically proven mild or moderate bladder outlet obstruction and concomitant detrusor instability. All patients were initially treated with 0.4 mg. tamsulosin orally once a day. A week later the patients were randomly allocated into group 1-25 who continued treatment with tamsulosin only and, group 2-25 who also received 2 mg. tolterodine orally twice daily. Reevaluation with a quality of life questionnaire and urodynamic study was performed after 3 months.

RESULTS

Two patients from group 2 stopped tolterodine while 1 patient from each group stopped tamsulosin because of hypotension. Analysis revealed statistically significant improvement in quality of life scores only in group 2 patients (mean score 525.0 and 628.4 before and after treatment, respectively, 2-sided t test p = 0.0003). A significant difference was noted in both groups after treatment for maximum flow rate and volume at first contraction. Additionally, in group 2, a statistically significant difference was observed for maximum detrusor pressure and maximum unstable contraction pressure after treatment.

CONCLUSIONS

Combination treatment with an alpha-blocker (tamsulosin) plus an anticholinergic (tolterodine) improves quality of life in patients with bladder outlet obstruction and concomitant detrusor instability. Interestingly, no acute urinary retention was observed and tolterodine did not affect the quality of urine flow or residual urine volume. The proposed combination appears to be an effective and relatively safe treatment option in patients with bladder outlet obstruction and detrusor instability.

Long-term results of multimodal therapy for chronic prostatitis/chronic pelvic pain syndrome

PURPOSE

Chronic prostatitis/chronic pelvic pain syndrome is a prevalent and multifactorial condition. Many patients have the condition for years despite conventional therapies. We assess the outcomes of multimodal therapy in patients with long-standing chronic prostatitis/chronic pelvic pain syndrome.

MATERIALS AND METHODS

A total of 53 patients with chronic prostatitis treated at our clinic with a minimum followup of 6 months were assessed by the National Institutes of Health-Chronic Prostatitis Symptom Index and by a global assessment score. Treatments included antibiotics, prostatic massage, anti-inflammatory phytotherapy, alpha-blockers and neuromuscular agents.

RESULTS

Mean age patient was 45 years and median symptom history was 3.5 years. Based on localizing cultures, and microscopy of urine and prostatic fluid 13% of the cases were category II, 41% were category IIIa and 46% were category IIIb. Mean followup from the last visit was 417 days (range 185 to 1,247). Mean changes +/- SE from the initial to the final score on the National Institutes of Health-Chronic Prostatitis Symptom Index were 10.4 +/- 3.3 to 5.9 +/- 4.4 for pain, 4.2 +/- 2.9 to 2.0 +/- 2.7 for urinary, 8.2 +/- 2.9 to 4.7 +/- 3.4 for quality of life and 22.7 +/- 6.6 to 13.2 +/- 9.5 for total score (p <0.0001). Based on a global subjective assessment 43 of the patients (80%) were better, 8 were the same and 3 were worse. At final assessment 39% of the patients were on no therapy, 22% were on an alpha-blocker, 37% were on quercetin, 13% were on neuromuscular agents and 9% were on antibiotics.

CONCLUSIONS

An approach using stepwise therapy with antibiotics, anti-inflammatories and neuromuscular agents can be successful in the majority of patients with long-standing chronic prostatitis.