103 Archivio Italiano di Urologia e Andrologia 2014; 86, 2 ORIGINAL PAPER Medical expulsive therapy for distal ureteric stones: tamsulosin versus silodosin Vittorio Imperatore 1 , Ferdinando Fusco 2 , Massimiliano Creta 1 , Sergio Di Meo 1 , Roberto Buonopane 1 , Nicola Longo 2 , Ciro Imbimbo 2 , Vincenzo Mirone 2 1 Department of Urology, Buon Consiglio Fatebenefratelli Hospital, Naples, Italy; 2 Department of Urology, Policlinico Federico II of Naples, Naples, Italy. Objectives: To compare the efficacy and safety of tamsulosin and silodosin in the context of medical expulsive therapy (MET) of distal ureteric stones. Patients and methods: Observational data were collected retrospectively from patients who received silodosin (N = 50) or tamsulosin (N = 50) as MET from January 2012 to January 2013. Inclusion criteria were: patients aged ≥ 18 years with a single, unilateral, symptomatic, radiopaque ureteric stone of 10 mm or smaller in the largest dimension located between the lower border of the sacroiliac joint and the vesico-ureteric junction. Stone expulsion rate, stone expulsion time, number of pain episodes, need for analgesics use, incidence of side effects were compared. Results: Stone-expulsion rate in the silodosin and in the tamsulosin groups were 88% and 82%, respectively (p not significant). Mean expulsion times were 6.7 and 6.5 days in the silodosin and tamsulosin group, respectively (p not significant). Mean number of pain episodes were 1.6 and 1.7 in the silodosin and tamsulosin group, respectively (p not significant). The mean number of analgesic require- ment was 0.84 and 0.9 for the silodosin and tamsulosin group, respectively (p not significant). Overall, incidence of side effects was similar in both groups. Patients taking silodosin experienced an higher incidence of retrograde ejaculation but a lower incidence of side effects related to peripheral vasodilation when compared to patients taking tamsulosin. Subgroup analysis demonstrated significantly lower mean expulsion times and pain episodes in patients with stones ≤ 5 mm in both groups. Conclusions: Tamsulosin and silodosin are equally effec- tive as MET for distal ureteric stones sized 10 mm or smaller. MET with silodosin is associatd with a lower incidence of side effects related to peripheral vasodila- tion but an higher incidence of retrograde ejaculation when compared to tamsulosin. KEY WORDS: Silodosin; Tamsulosin; Medical expulsive therapy; Stones. Submitted 26 August 2013; Accepted 15 January 2014 Summary No conflict of interest declared. IntroDuCtIon Ureteric stones account for 20% of urinary tract stones and about 70% of them are found in the lower third of the ureter at presentation (1). To date, minimally inva- sive therapies, such as extracorporeal shock wave lithotripsy and ureterolithotripsy, represent efficacious treatment modalities in almost all cases. Nevertheless, these procedures imply high costs and are not risk-free (2). A watchful waiting approach has been reported to be associated with spontaneous stone expulsion in up to 50% of cases but some complications may occur such as urinary tract infections, hydronephrosis and colic events (2). In recent years, the use of the expectant approach for distal ureteric stones has been extended thanks to the use of adjuvant medical expulsive therapy (MET), that is able to reduce symptoms and facilitate stone expulsion. In 1970, Malin et al. demonstrated the presence of alpha and beta adrenergic receptors (AR) in the human ureter (3). Alpha1 are the most abundant AR subtypes at the level of ureteric smooth muscle cells (4). Itoh et al. demonstrated that three types of alpha1 AR are expressed in the human ureter (alpha1A, alpha1B and alpha1D) (5-7). Antagonists of these receptors have been proved to decrease ureteric basal tone, peristaltic activi- ty, and contractions thus decreasing intraureteric pres- sure and increasing urine transport (5). Three meta- analyses have confirmed a positive effect of alpha-block- er therapy on the stone expulsion rates (8-11). Alpha- blockade has been proved to improve the likelihood of spontaneous stone passage, and to decrease both the time to stone passage and analgesic requirements (12). According to European Association of Urology Guidelines, alpha-blockers or nifedipine are recommended for MET (grade of recommendation A) (13). Patients who elect for MET should have well controlled pain, no clinical evi- dence of sepsis, and adequate renal functional reserve (13). The alpha1A/D selective alpha-blocker tamsulosin has been demonstrated to be a safe and effective drug that enhances spontaneous passage of distal ureteral stones sized 10 mm or smaller (8). Recent studies have demonstrated that the alpha1A subtype plays the major role in mediating phenylephrine-induced contraction in DOI: 10.4081/aiua.2014.2.103