Pharmacologic Expulsive Treatment of Ureteral Calculi

Assessing safety and tolerability of super selective alpha-1 adrenergic blockers in infants under 3 years: Insights from a single-center study on lower urinary tract obstruction (LUTO)

BACKGROUND

Little is known about alpha blocker use in young children, particularly in those with lower urinary tract obstruction (LUTO). Therefore, we aimed to assess the safety and tolerability of selective alpha-blockers in children under 3 years of age with LUTO.

METHODS

A prospectively-collected database captured 93 patients born between 12/2005 and 01/2023. Assessed data included baseline characteristics, ultrasound features, blood pressure (BP), side effects and creatinine values. Primary outcome was side effects or discontinuation of alpha-blockers. Secondary outcomes were BP parameters, growth, and kidney function. Data are shown as median with interquartile range (IQR), Odds Ratio (OR) with 95% CI and mean value with standard deviation (SD).

RESULTS

A total of 33 patients less than 3 years of age were started on alpha-blockers at 16.8 ± 11.8 months and followed for 48.9 ± 40.5 months. At last follow-up, no significant effect on systolic/diastolic BP percentiles (p > 0.9 and p > 0.9), creatinine levels (p > 0.9). Weight percentiles increased to the last follow-up (37.8 ± 33.2 vs. 53.6 ± 32.9, p = 0.0133) while height percentiles increased from 28 to 100 days to last follow-up (12.9 ± 18.3 vs. 39.6 ± 35.2, p=0.001). Four patients discontinued alpha-blockers; however, no side-effects were reported during the study period.

CONCLUSIONS

No severe clinical or systemic side effects were observed, demonstrating safety and tolerability in young children with LUTO. Although alpha-blockers did not significantly improve kidney function in short term follow-up, and failure to thrive was not observed in these children. Additional studies with more patients are required to assess the optimal dosing and timing leading to maximal benefits for these infants.

Evaluation of the efficacy and safety of either or both mirabegron and silodosin, as a medical expulsive therapy for distal ureteric stones

OBJECTIVE

To evaluate efficacy and safety of either or both silodosin and mirabegron as MET for distal ureteric stones ≤ 10 mm.

PATIENTS AND METHODS

This study enrolled a total of 105 patients, aged between 20 and 56 years, diagnosed by single radiopaque distal ureteral stone measuring ≤ 10 mm. The recruitment period spanned from May 2020 to December 2021. The patients were randomly divided into three groups, with each group consisting of 35 participants. Group A received a once-daily dose of 8 mg of silodosin, group B received a once-daily dose of 50 mg of mirabegron, and group C received a combination of both medications. Treatment was administered to all patients until the stone was expelled or for a maximum duration of four weeks. The stone-free rate was determined by analyzing KUB films with or without ultrasonography.

RESULTS

The rate of stone expulsion was significantly higher in group C compared to groups A and B (P = 0.04 and P = 0.004, respectively). The mean (standard deviation) time for stone expulsion in groups A, B, and C was 14 ± 2.3 days, 11 ± 3.1 days, and 7 ± 2.2 days, respectively. Group C demonstrated a significantly shorter stone expulsion time compared to groups A and B (P = 0.001 and P = 0.04, respectively). The frequency of renal colic in group C was significantly lower than that in groups A and B, resulting in a reduced requirement for analgesics (P < 0.05). Anejaculation occurred at a significantly higher rate in the silodosin group (73.9%) and combination group (84%) compared to the mirabegron group (P < 0.05).

CONCLUSIONS

The findings of this study suggest that both silodosin and mirabegron are effective treatments for the expulsion of lower ureteric stones. Furthermore, the combination of these medications leads to an increased rate of stone expulsion and a reduced duration of expulsion.

Does mirabegron have a potential role as a medical expulsive therapy in the treatment of distal ureteral stones? A prospective randomized controlled study

BACKGROUND

The existence of β3 receptors in the bladder and ureter was documented in many studies on animals and humans, it was documented that relaxation of the lower ureteral segment is achieved by the stimulation of these receptors. Our aim was to assess the efficacy and safety of mirabegron as a medical expulsive therapy (MET) for distal ureteral stones in comparison with silodosin and placebo.

METHODS

One hundred eighty patients with distal ureteral stone of 5-10 mm size were included in our study. They were divided into three groups, and each one consisted of 60 patients. Group I was given silodosin 8 mg, group II mirabegron 50 mg and group III placebo once daily. The treatment was prescribed for all the cases till stone expulsion or a maximum duration of 4 weeks. Primary outcome was the stone expulsion rate (SER). While secondary outcomes were stone expulsion time, side effects of the used drugs, hospital visits number for pain, and amount of analgesic taken.

RESULTS

We found that the SER was significantly higher in silodosin than mirabegron and placebo groups (61%, 38.6%, and 36.7%, respectively) (p = 0.013). Also, the stone expulsion interval was significantly shorter in silodosin than mirabegron and control groups (p < 0.001). While hospital visits number for pain, and amount of analgesic taken were comparable. There was no difference between the studied medications in terms of the adverse effects except for retrograde ejaculation (silodosin = 63.3%, mirabegron = 0%, and placebo = 0%; p < 0.001).

CONCLUSION

Mirabegron has no medical expulsive effect. While silodosin improves SER and stone expulsion time. However, retrograde ejaculation was its main side effect and occurred in 63.3% of the male patients. Therefore, more research is needed to discover a more tolerable MET.

Medical Expulsive Therapy for Pediatric Ureteral Stones: A Meta-Analysis of Randomized Clinical Trials

To evaluate the efficacy and safety of medical expulsive therapy (MET) for ureteral stones in pediatric patients, Cochrane, PubMed, Web of Science, Scopus, and the reference list of retrieved studies were searched up to September 2022 to identify RCTs on the efficacy of MET. The protocol was prospectively registered at PROSPERO (CRD42022339093). Articles were reviewed, data were extracted by two reviewers, and the differences were resolved by the third reviewer. The risk of bias was assessed using the RoB2. The outcomes, including the stone expulsion rate (SER), stone expulsion time (SET), episode of pain, analgesic consumption, and adverse effects, were evaluated. Six RCTs enrolling 415 patients were included in the meta-analysis. The duration of MET ranged from 19 to 28 days. The investigated medications included tamsulosin, silodosin, and doxazosin. The stone-free rate after 4 weeks in the MET group was 1.42 times that of the control group (RR: 1.42; 95% CI: 1.26-1.61, p < 0.001). The stone expulsion time also decreased by an average of 5.18 days (95% CI: -8.46/-1.89, p = 0.002). Adverse effects were more commonly observed in the MET group (RR: 2.18; 95% CI: 1.28-3.69, p = 0.004). The subgroup analysis evaluating the influence of the type of medication, the stone size, and the age of patients failed to reveal any impact of the aforementioned factors on the stone expulsion rate or stone expulsion time. Alpha-blockers as medical expulsive therapy among pediatric patients are efficient and safe. They increase the stone expulsion rate and decrease the stone expulsion time; however, this included a higher rate of adverse effects, which include headache, dizziness, or nasal congestion.

A Concise and Useful Guide to Understand How Alpha1 Adrenoceptor Antagonists Work

Adrenoceptors are the receptors for the catecholamines, adrenaline and noradrenaline. They are divided in α (α1 and α2) and β (β1, β2 and β3). α1-Adrenoceptors are subdivided in α1A, α1B and α1D. Most tissues express mixtures of α1-adrenoceptors subtypes, which appear to coexist in different densities and ratios, and in most cases their responses are probably due to the activation of more than one type. The three subtypes of α1-adrenoceptors are G-protein-coupled receptors (GPCR), specifically coupled to Gq/11. Additionally, the activation of these receptors may activate other signaling pathways or different components of these pathways, which leads to a great variety of possible cellular effects. The first clinically used α1 antagonist was Prazosin, for Systemic Arterial Hypertension (SAH). It was followed by its congeners, Terazosin and Doxazosin. Nowadays, there are many classes of α-adrenergic antagonists with different selectivity profiles. In addition to SAH, the α1-adrenoceptors are used for the treatment of Benign Prostatic Hyperplasia (BPH) and urolithiasis. This antagonism may be part of the mechanism of action of tricyclic antidepressants. Moreover, the activation of these receptors may lead to adverse effects such as orthostatic hypotension, similar to what happens with the antidepressants and with some antipsychotic. Structure-activity relationships can explain, in part, how antagonists work and how selective they can be for each one of the subtypes. However, it is necessary to develop new molecules which antagonize the α1-adrenoceptors or make chemical modifications in these molecules to improve the selectivity, pharmacokinetic profile and/or reduce the adverse effects of known drugs.

Efficacy of Mirabegron as Medical Expulsive Therapy for Distal Ureteral Stones: A Prospective, Randomized, Double-Blinded, Controlled Study

BACKGROUND

Today, medical expulsive therapy (MET) is more effective and commonly used in distal ureteral stones when compared with conservative treatments. Many treatments, namely, alpha-adrenergic blockers and calcium channel blockers, prostaglandin synthesis inhibitors, glyceryl trinitrate, and steroids, have been, therefore, utilized to mitigate such complications and accelerate stone expulsion. Several animal and human studies revealed the presence of β3-receptors in the ureter and bladder, where stimulating these receptors could relax the distal ureteral segment.

OBJECTIVES

The aim of the study was to evaluate the efficacy of use of mirabegron as MET for distal ureteral stones (intramural and extramural).

METHODS

This is a prospective randomized controlled study including 90 patients who had distal ureteral stones less than 10 mm and were evaluated between January and June 2020. The patients were classified into 3 groups: group (A) 30 patients: mirabegron 50 mg d-1 + diclofenac Na 100 mg tab (to be taken only during colic episodes), group (B) 30 patients: tamsulosin HCL 0.4 mg cap + diclofenac Na 100 mg tab (to be taken only during colic episodes), and group (C) 30 patients: diclofenac Na 100 mg tab only (to be taken only during colic episodes). Age, sex, stone size, laterality, and grade of ureterohydronephrosis were recorded. Patients were observed for 30 days, and ureteroscopy was completed for those with nonexpulsed stones. Follow-up parameters included number of renal colic episodes, duration of medical therapy, stone expulsion time, and stone expulsion rate (SER).

RESULTS

In the group (A), 2 (6.6%) patients were excluded due to nasal congestion, and 1 (3.3%) patient was excluded due to a 20-mm Hg systolic blood pressure increase. Four (13.3%) patients in group (B) were noncompliant on medical treatment. In addition, 2 (6.6%) patients in group (A), 1 (3.3%) patient in group (B), and 5 (16.6%) patients in group (C) who did not attend follow-up examinations were excluded from the study. The SER increased significantly in group (A) and (B) when compared with group (C). The mean time of stone expulsion was about 15, 25, and 12 days for groups A, B, and C, respectively, and there was a significant statistical difference (p value = 0.006) among the 3 groups. The mean number of renal colic episodes of group (A) of patients was 1.8 times, while that of group (B) was 2.6 times and that of group (C) was 2.16 times with no significant statistical difference after comparing the 3 groups (p value = 0.660).

CONCLUSIONS

Treatment with mirabegron appears to be a safe and effective medical expulsion therapy for distal ureteric stones and is better than tamsulosin.

Meta-Analysis of the Safety and Efficacy of α-Adrenergic Blockers for Pediatric Urolithiasis in the Distal Ureter

OBJECTIVE

Pediatric urolithiasis is a common condition, and medical expulsive therapy has grown to be accepted by many parents. We carried out a meta-analysis to identify the efficacy and safety of α-adrenergic blockers for the treatment of pediatric urolithiasis.

METHODS

We identified related articles from the PubMed, Embase, and Cochrane Library databases. All published randomized controlled trials (RCTs) describing the use of α-adrenergic blockers and placebo treatment for pediatric distal urolithiasis were involved. The outcomes included stone expulsion rate, stone expulsion time, pain episodes, need for analgesia, adverse events, and related subgroup analyses.

RESULTS

A total of nine RCTs were involved in our study, including 586 patients. We found that α-adrenergic blockers could significantly increase the rate of stone expulsion [odds ratio (OR), 3.49; 95% confidence interval (CI), 2.38-5.12; p < 0.00001], reduce the stone expulsion time [mean difference (MD), -5.15; 95% CI, -8.51 to -1.80; p = 0.003], and decrease pain episodes (MD, -1.02; 95% CI, -1.33 to -0.72; p < 0.00001) and analgesia demand (MD, -0.92; 95% CI, -1.32 to -0.53; p < 0.00001) but had a higher incidence of side effects (MD, 2.83; 95% CI, 1.55 to 5.15; p = 0.0007). During subgroup analyses, different medications (tamsulosin, doxazosin, and silodosin) also exhibited better efficiencies than placebo, except for doxazosin, which showed no difference in expulsion time (MD, -1.23; 95% CI, -2.98 to 0.51; p = 0.17). The three kinds of α-adrenergic blockers also appeared to be better tolerated, except for tamsulosin with its greater number of adverse events (MD, 2.85; 95% CI, 1.34 to 6.03; p = 0.006). Silodosin led to a better expulsion rate than tamsulosin (OR, 0.42; 95% CI, 0.20 to 0.92; p = 0.03). In addition, α-adrenergic blockers increased the stone expulsion rate regardless of stone size and decreased the expulsion time of stones measuring <5 mm (MD, -1.71; 95% CI, -2.91 to -0.52; p = 0.005), which was not the case for stones measuring >5 mm in expulsion time (MD, -3.61; 95% CI, -10.17 to 2.96; p = 0.28).

CONCLUSION

Our review suggests that α-adrenergic blockers are well-tolerated and efficient for treating pediatric distal urolithiasis. We also conclude that silodosin is the best choice of drug, offering a better expulsion rate, but it remains to be evaluated further by future studies.

The effect of preoperative tamsulosin on ureteroscopic access in school-aged children

INTRODUCTION

Flexible ureteroscopes are not tailored for pediatric ureteral size and may not pass at first attempt into the pediatric ureter. Administration of tamsulosin preoperatively in adults has been shown to facilitate ureteral access sheath placement. Several studies have shown tamsulosin to be safe and effective when utilized for medical expulsive therapy in pediatric patients, but its utility for preoperative ureteral dilation has not been studied to date.

OBJECTIVE

We hypothesized that preoperative tamsulosin reduces failed ureteroscopic access in children.

MATERIALS AND METHODS

We conducted a retrospective review of patients aged 0-18 years undergoing flexible ureteroscopy (URS) from 2014 to 2019 at a single institution. Patients were divided into those taking 0.4 mg of tamsulosin daily for at least 1 week prior to surgery and those not taking tamsulosin. The primary outcome was failure to pass a 7.95 Fr flexible ureteroscope on initial attempt, requiring stent placement and staged management. Patients undergoing URS or stent placement within the prior year, requiring semi-rigid URS, or with genitourinary anomalies were excluded.

RESULTS AND DISCUSSION

A total of 49 patients met inclusion criteria. The tamsulosin group (n = 13) and non-tamsulosin group (n = 36) were similar with respect to demographic data. The percentage of prepubertal patients was 53% vs 33% (p = 0.19). The tamsulosin group had lower failed URS (38% vs 61%, p = 0.20). When stratified by age, both prepubertal and postpubertal patients in the tamsulosin group had lower failed URS (43% vs 67%, p = 0.67 and 33% vs 58%, p = 0.38). These clinically significant results suggest initial passage of a flexible ureteroscope is more successful in pediatric patients on preoperative tamsulosin. This study was largely limited by its low power and flaws inherent to its retrospective design.

CONCLUSION

Our results have implications for prescribing tamsulosin preoperatively to reduce multiple procedures and anesthetics in children. Adequately powered prospective trials are warranted to confirm preoperative tamsulosin reduces failed first-attempt flexible URS in children.

Mirabegron in medical expulsive therapy for distal ureteral stones: a prospective, randomized, controlled study

OBJECTIVE

To observe the efficacy and safety of Mirabegron in patients with distal, ureteral stones ≤ 10 mm.

PATIENTS AND METHODS

A total of 90 patients with distal ureteral stones ≤ 10 mm were prospectively randomized into two groups. Forty-five cases in the study group and 45 cases as control. The stone-free rates (SFRs) and renal colic episodes between two groups were compared at the 1st, 2nd and 4th week end by imaging examinations.

RESULT

All of 90 patients were randomly assigned to two groups. In patients with ≤ 5 mm stones, the SFRs in the 1st week (63.6% vs. 33.3%, P = 0.040), the 2nd week (86.4% vs. 54.2%, P = 0.018), and the 4th week (90.9% vs. 66.7%, P = 0.046) after treatment were all significantly higher than that in the control group by the stratification analysis of stone size. Even though SFRs were all higher for patients with > 5 mm stones in study group, there was no statistically significant difference (All P > 0.05). In terms of renal colic episodes, the frequency of occurrence of the study group was significantly lower than that of the control group and need less antalgic.

CONCLUSIONS

The MET with Mirabegron has a significant role in improve SFR for the patients with distal ureteral stones ≤ 5 mm and no effect in > 5 mm stones. Furthermore, Mirabegron reduces the need for antalgic in ≤ 10 mm stones with low incidence of adverse effects.

Efficacy of combination terazosin and nifedipine therapy in postoperative treatment of distal ureteral stones after transurethral ureteroscopic lithotripsy

Objective

Methods

Results

Conclusion

Efficacy of mirabegron in medical expulsive therapy

To show the efficacy of mirabegron for medical expulsive treatment, in patients had intramural located distal ureteral stone. A 80 patients had intramural ureteral stone were assessed retrospectively between April 2017 and January 2018. Mirabegron 50 mg/day + diclofenac 100 mg/day (group 1, n = 40), and only diclofenac 100 mg/day (group 2, n = 40) were administered to patients, consecutively. Age, gender, stone size, laterality, and severity of hydronephrosis were recorded. Spontaneous stone expulsion rates (SER), stone expulsion time, and the number of daily colic episodes were evaluated. In the group 1, one (2.5%) patient was excluded due to nasopharyngitis, and one (2.5%) patient was excluded due to 5 mmHg systolic blood pressure increase. In addition, four (10%) patients in group 1, and six (15%) patients in group 2, who did not attend follow-up examinations, were excluded from the study. There was not any statistically significant difference between the two groups in terms of age, gender, stone location, severity of hydronephrosis, stone size (p = 0.736, p = 0.310, p = 0.467, p = 0.801, p = 0.761, consecutively). Spontaneous expulsion ratios were calculated as 73.52% in group 1, and 47.05% in group 2 (p = 0.026). However, there was not any statistically significant difference in terms of stone expulsion time (p = 0.979). SER for patients had ≤ 6 mm stones was higher in group 1 (87.5 vs 52.49%, p = 0.031). In addition, group 2 patients had more pain episodes (1.02 ± 0.52 vs. 1.29 ± 0.57, p = 0.049). In the current study, mirabegron has been shown to be an efficient, safe and a new treatment modality, with lower side effect profile for the intramural located distal ureteral stones.

Silodosin in the treatment of distal ureteric stones in children: A prospective, randomised, placebo-controlled study

Objectives

To evaluate the possible role of silodosin (a highly selective α_1A-adrenoceptor antagonist) in facilitating the passage of distal ureteric stones (DUS) in children, as the role of α-blockers as medical expulsive therapy is well known in adults.

Patients and methods

In all, 40 paediatric patients (27 boys and 13 girls) diagnosed with unilateral, single, radiopaque DUS of <10 mm were included in the study. Their mean (SD, range) age was 8.1 (2.7, 5–17) years. The patients were randomly divided into two groups: Group A, received silodosin 4 mg as a single bedtime dose; and Group B, received placebo as a single bedtime dose. Ibuprofen was prescribed to both groups on-demand for pain episode relief. Patients were followed up biweekly for 4 weeks. The stone expulsion time and rate, pain episodes, analgesic use, and any adverse effects were recorded.

Results

The mean (SD) stone size in Group A was 6.6 (1.7) mm and in Group B was 6.7 (1.4) mm (P = 0.4). Two patients were lost to follow-up (one from each group), and one patient in Group A refused to complete the study. The stone-free rate at end of the 4-week treatment period was 88.8% in Group A vs 73.6% in Group B (P = 0.4). The mean (SD) stone expulsion time was 7.0 (4.3) vs 10.4 (4.7) days in groups A and B, respectively (P = 0.02). The mean (SD) number of pain episodes requiring ibuprofen was 2.3 (1.4) vs 4.7 (2.6) episodes in groups A and B, respectively (P < 0.001). Adverse effects (headache and dizziness) were recorded in three patients (16.7%) in Group A, which were mild and none of them discontinued treatment, whilst no adverse effects were recorded in Group B.

Conclusions

The data in the present study show that silodosin can be safely used in the treatment of DUS in children for decreasing time to stone expulsion, pain episodes, and analgesic requirement.

The efficacy and safety of adrenergic alpha-antagonists in treatment of distal ureteral stones in pediatric patients: A systematic review and meta-analysis

OBJECTIVE

We carried out a systematic review and meta-analysis to evaluate the efficacy and safety of adrenergic alpha-antagonists as a medical expulsive therapy for ureteral stones in pediatric patients.

METHODS

The PubMed, EMBASE and Cochrane Controlled Trials Register databases were searched up to January 2016. All randomized controlled trials and all cohort studies in which patients were randomized to receive either adrenergic alpha-antagonists or placebo for ureteral stones were identified. The outcome measures assessed were overall stone expulsion rate (primary), expulsion time (secondary), and treatment-emergent adverse events.

RESULTS

Five trials with a total of 406 pediatric patients met the inclusion criteria. According to the doses of adrenergic alpha-antagonists, the pooling effects of adrenergic alpha-antagonists were analyzed, with a higher expulsion rate obtained than in controls, the stone expulsion rate (OR=2.70, 95% CI 1.49 to 4.91, P=0.001). Adrenergic alpha-antagonists statistically did not significantly decrease the number of the stone expulsion time with the placebo, the stone expulsion time (SMD=-4.65, 95% CI -9.76 to 0.45, P=0.07). Safety assessments included common treatment-emergent adverse events (TEAEs) (OR=2.01, 95% CI 0.74 to 5.48, P=0.17). Compared with placebos, there was a higher stone expulsion rate with the adrenergic alpha-antagonists; in addition, fewer adverse effects were observed.

CONCLUSIONS

This meta-analysis may suggest that adrenergic alpha-antagonists are a safe and effective medical expulsive therapy choice for ureteral stones in pediatric patients. As the level of classification of evidence-based medicine, the level of evidence of our article is Ia. But it remains to need a large-scale multicenter randomized controlled study to be further confirmed.

LEVEL OF EVIDENCE

The level of evidence of our study is V.

Medical expulsive treatment in pediatric urolithiasis

The frequency of stone disease in childhood ranges between 0.1-5 percent. Stone disease occurs as a result of enviromental, metabolic, anatomical, infectious and nutritional factors. Percutaneous nephrolitotomy, uretherorenoscopy, laparoscopic surgery, open surgery and extracorporeal shock wave lithothripsy are treatment alternatives for stone disease during childhood. However, these methods are not completely innocent. Some complications may occur after these procedures. These procedures are generally not cost- effective. Even invasive procedures have high success rates, so medical expulsive treatment modalities have become an alternative for a group of patients. Nonsteroidal anti- inflammatory drugs, antimuscarinic drugs, phospodiesterase type 5 inhibitors, steroids, calcium channel blockers and alpha blockers are treatment alterneatives used for this modality in the literature. The drug is chosen according to the location, size, and composition of the stone, recent technology, cost, surgeon's experience and surgeon's and the parents' preferences. In this review article the following topics will be discussed such as "Why medical expulsive treatment is needed during childhood? Which drug should be chosen for which stone type? How long should a treatment of urolithiasis last?

Tamsulosin for the management of distal ureteral stones in children: a prospective randomized study

PURPOSE

Based on efficacy demonstrated in the adult population, tamsulosin was evaluated with regard to facilitating ureteral stone expulsion in children presenting with distal ureteric calculi.

PATIENTS AND METHODS

A prospective randomized controlled study involving 61 children with distal ureteric calculi <12 mm was performed. The children were randomly divided into two groups. Group I (study group, n = 33) received tamsulosin and standard analgesia, and Group II (placebo group, n = 28) received standard analgesia and placebo. Patients were offered a closely monitored trial for spontaneous stone passage in the 4-week period prior to definitive therapy. The stone expulsion rate, number and duration of pain episodes, need for analgesia and possible side effects of medications were observed.

RESULTS

All patients completed the study and none were excluded due to side effects. No significant differences were found between the groups for age, gender and stone size. Mean patient age was 8.1 ± 6.8 years. There were 25 females and 36 males. The stone-free rate was 87.8% in Group I (29/33), compared with 64.2% (18/28) in Group II. A mean stone expulsion time of 8.2 and 14.5 days was recorded for Group I and II respectively, and this difference was statistically significant (P < 0.001).

CONCLUSIONS

Medical expulsion therapy for lower ureteric stones is a successful procedure in children. Tamsulosin demonstrated no clinically significant adverse effect, while proving to be a safe and effective treatment option.

[From lab to clinical activity: adrenergic receptors and human uro-genital tissues]

BACKGROUND

Nowadays translational medicine is acquiring a more and more important role in connecting laboratory experimental results on human tissues to clinical findings and drug employment. We want to underline the importance of in vitro studies, which have been extensively performed on animal organs, but few studies have been performed on human tissues. Nevertheless, a more accurate result when compared to the in vivo use of drugs can be given only by testing the very same human tissues in a lab. We related clinical treatments of different pathologies with the results obtained in laboratory studying in vitro fragments of human organs extracted during surgery exposed to different mediators and drugs.

METHODS

Fragments of urethers, bladder (detrusorial muscle and bladder neck muscle fibers), corpora cavernosa, and vas deferens were extracted during demolitive surgery trying not to traumatize the tissue, in order to keep it alive and not to ruin its contractile fibers. The fragments were then put into polisaline solution and, once in the laboratory, fixed on suitable isolated organ support, fixed at one side of the thermostatic pool and on the other side connected to a digital monitoring system. The contractility was then studied after adding different mediators.

RESULTS

The urethers have shown a stronger response to NE and PGF2a, with a different contractility in their distal part due to a major concentration of alpha-receptors; the bladder neck has also shown a strong contractile response to NE and PGF2a, and is inhibited by alpha-blockers; the bladder detrusor, instead, responds to ACH (acetylcholine) and PGF2a; the vas deferens shows a different type of contractility in the prostatic part compared to the epididimary part when stimulated with noradrenaline and PGF2a; the corpora cavernosa respond to NE and PGF2a.

CONCLUSIONS

The results obtained after stimulating the fragments can explain and prove the receptorial activity of inner mediators and of commonly used drugs which have, for years, been used empirically; the simplicity and repetitivity of the method can be considered and used not only to research the physiological functioning of different organs, but also the functioning of new drugs before testing them on patients, being more reliable and accurate than tests on animal tissues. This experimental work has shown that using human tissues in testing specific mediators is the most reliable laboratory method.

α(1)-Adrenoceptors in the urinary tract

α(1)-Adrenoceptors have been identified and characterized extensively by functional, radioligand-binding, and molecular biological techniques. Molecular clones have been isolated for three α(1)-subtypes (α(1a), α(1b), and α(1d)), and these subtypes are also functionally characterized. α(1)-Adrenoceptors are present in the prostate, urethra, bladder (urothelium, smooth muscle, and afferent nerves), ureter, vas deferens, peripheral ganglia, nerve terminals, vascular tissues, and central nervous system (CNS), and they could all potentially influence overall urinary function and contribute to both the therapeutic and adverse effects of α(1)-adrenoceptor antagonists in patients with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). This review aimed to discuss the relevant physiological and pharmacological roles and molecular biology of α(1)-adrenoceptor subtypes in the prostate, urethra, bladder, ureter, and CNS.

Efficacy of Tamsulosin with Extracorporeal Shock Wave Lithotripsy for Passage of Renal and Ureteral Calculi

Objective:

To review the evidence for the safety and efficacy of adjunctive tamsulosin in enhancing the efficacy of renal and ureteral stone clearance when used with extracorporeal shock wave lithotripsy (ESWL).

Data Sources:

A search of MEDLINE (1950-January 2008), PubMed (1950-January 2008), and the Iowa Drug Information System (1966-January 2008) was performed using the search terms tamsulosin and extracorporeal shock wave lithotripsy. MeSH headings included lithotripsy and adrenergic α-antagonists. Additional references were found by searching bibliographic references of resulting citations.

Study Selection and Data Extraction:

All studies utilizing tamsulosin therapy after a single session of ESWL or after the development of steinstrasse, an accumulation of stone fragments that obstructs the ureter, were included.

Data Synthesis:

To date, 5 prospective studies have evaluated the efficacy of tamsulosin combined with ESWL in enhancing the passage of renal and ureteral stones. in one trial, 12-week renal stone clearance was 60% in the control group compared with 78.5% in the tamsulosin group (p = 0.037). Among trials that evaluated overall ureteral stone clearance, efficacy rates were 33.3-79.3% in the control groups compared with 66.6-96.6% in the tamsulosin groups. Reports of pain and supplemental analgesic dosing were consistently lower with tamsulosin, but data on the incidence of subsequent retreatment with ESWL or ureteroscopy was rarely reported. Adjunctive tamsulosin particularly enhanced the passage of renal stones 10-24 millimeters in diameter. Overall, tamsulosin was well tolerated.

Conclusions:

Overall, evidence suggests that adjunctive tamsulosin therapy combined with ESWL is safe and effective in enhancing stone clearance in patients with renal stones 10-24 millimeters in diameter. Evidence regarding ureteral stone clearance is inconclusive, although adjunctive tamsulosin has been reported to reduce painful episodes. Larger prospective trials evaluating different dosages and stone locations, as well as the ability of tamsulosin to reduce repeat ESWL or more invasive methods such as ureteroscopy should be performed.

A systematic review of medical therapy to facilitate passage of ureteral calculi

STUDY OBJECTIVE

Acute renal colic is a common presenting complaint to the emergency department. Recently, medical expulsive therapy using alpha-antagonists or calcium channel blockers has been shown to augment stone passage rates of moderately sized, distal, ureteral stones. Herein is a systematic evaluation of the use of medical expulsive therapy to facilitate ureteral stone expulsion.

METHODS

We searched the databases of MEDLINE, EMBASE, and the Cochrane Controlled Trials Register. Additional sources included key urologic journals and bibliographies of selected articles. We included studies that incorporated a randomized or controlled clinical trial design, patients older than 18 years, treatment in which an alpha-antagonist or calcium channel blocker was compared to a standard therapy group, and studies that reported stone expulsion rates. A random effects model was used to obtain summary risk ratios (RRs) and 95% confidence intervals (CIs) for stone expulsion rate.

RESULTS

A pooled analysis of 16 studies using an alpha-antagonist and 9 studies using a calcium channel blocker suggested that the addition of these agents compared to standard therapy significantly improved spontaneous stone expulsion (alpha-antagonist RR 1.59; 95% CI 1.44 to 1.75; number needed to treat 3.3 [95% CI 2.1 to 4.5]; calcium channel blocker RR 1.50; 95% CI 1.34 to 1.68; number needed to treat 3.9 [95% CI 3.2 to 4.6]) in patients with distal ureteral stones. Subgroup analysis of trials using concomitant medications (ie, low-dose steroids, antibiotics, and elimination of trials using an anticholinergic agent) yielded a similar improvement in stone expulsion rate. Adverse effects were noted in 4% of patients receiving alpha-antagonist and in 15.2% of patients receiving calcium channel blockers.

CONCLUSION

Our results suggest that "medical expulsive therapy," using either alpha-antagonists or calcium channel blockers, augments the stone expulsion rate compared to standard therapy for moderately sized distal ureteral stones.