Efficacy of Mirabegron Versus Tamsulosin Versus Solifenacin for Treatment of Ureteral Stents-Related Symptoms

The primary objective of this prospective, single-centre randomized controlled trial is to assess the efficacy of three different drugs in treatment of ureteral stents related symptoms (Beta 3 adrenergic receptor agonist; Mirabegron 50mg) vs. (Alpha 1 adrenergic receptor antagonist; Tamsulosin 0.4mg) vs. (Anticholinergic; Solifenacin 10 mg) using validated symptoms questionnaires.

In addition, adverse events of the utilized medications will be monitored during study period as a secondary objective.

Indwelling ureteral stents are specialized catheters designed to alleviate obstruction by maintaining the patency of the ureteral lumen and to splint the ureter by acting as a scaffold to promote organized tissue healing. (1)

Common issues associated with contemporary ureteral stents include stent-related pain, hematuria, dysuria, urgency, infection, and encrustation (2). Majority of patients (80%) reported one or more urinary symptoms with over 80% of patients experience stent-related pain that affects daily activities, 58% report reduced work capacity, and 32%report sexual dysfunction (2). In addition, as many as 32% of patients had ureteral stents removed sooner than anticipated because of these complications (3).

Considering this high prevalence of ureteral stent related symptoms (uSRS) among patients and its potential impact on quality of life (QoL), adequate management of these bothering symptoms was the point of research over the last decades (4).

The exact mechanism involved in uSRS is not yet known; however, many authors report that such symptoms are associated with ureteral spasms, urinary reflux attributable to ureteral stent, or trigonal irritation (5).

Different novel types of stents have been developed and evaluated to reduce uSRS; however, there is still controversy regarding their clinical application (6). Conversely, pharmacological therapy, including anticholinergics and alpha-blockers, remains the most effective option to manage uSRS (7).

The role of a-blockers in reducing uSRS involves reduction of bladder outlet resistance to alleviate flank pain in male patients with preexisting bladder outlet obstruction (BOO). It has been proposed that relaxing the distal ureter and irritation of the trigone decreases bladder outlet resistance and voiding pressure, thereby potentially decreasing the incidence of renal reflux and subsequent flank pain (8) . Otherwise, anticholinergic agents may have an effect on involuntary contractions of the bladder induced by the distal end of ureteral stents with subsequent relief of uSRS (9).

The above-mentioned drugs, however, are not easy to apply to some patients with co-morbidities because of the potential side effects. The most common medication-related complications of a-blockers are dizziness and orthostatic hypotension. Depending on the type of medication, medication-related adverse events are reported at a rate of 5% to 20% (10). In addition, anticholinergic agents have various adverse effects that decrease treatment compliance, such as dry mouth, constipation, blurred vision and dyspepsia (11).

Beta-3 agonist mirabegron is believed to be responsible for the relaxation of the detrusor smooth muscle during the storage phase (12). It helps relax the detrusor smooth muscle, and results in increased bladder capacity without any changes in micturition pressure, post-void residual urine volume, or voiding contractions.

Considering the function of mirabegron as a therapeutic agent for overactive bladder (OAB), mirabegron is assumed to be effective for relieving voiding symptoms attributable to uSRS (13).

Eligibility Criteria:
Inclusion Criteria:

* Adult patients (aged 19-80 years)
* Undergo unilateral uncomplicated retrograde rigid ureteroscopy (URS) or retrograde intrarenal surgery (RIRS) with planned ureteral stent insertion.

Exclusion Criteria:

* Patients with neurogenic bladder, OAB syndrome, and neurological and psychiatric diseases
* Residual ureteral or renal stones after the procedure
* Preoperative febrile UTI
* pregnancy or breastfeeding
* Bilateral ureteroscopic surgery
* Single kidney
* Chronic kidney disease
* Cardiovascular or cerebrovascular disease
* Hepatic dysfunction
* History of pelvic surgery or irradiation
* History of bladder or prostate surgery
* Other acute medical conditions as acute gastroenteritis, osetoarthritis that might influence the patient QoL
* Preoperative indwelling of ureteral stent for relief of stone-related pain or sepsis