Is low-dose tadalafil better than tamsulosin? A randomized controlled trial in shockwave lithotripsy for solitary upper tract calculi

Objective To ascertain whether low-dose tadalafil (5 mg) is more efficient than tamsulosin (0.4 mg) in facilitating calculus expulsion in those receiving extracorporeal shockwave lithotripsy for solitary upper urinary tract calculi. Patients and Methods This was a triple-blinded, prospective, superiority, randomized controlled, single-centre trial. A total of 250 patients with solitary renal or ureteric calculus measuring 6-24 mm were randomized (1:1) to receive either 0.4 mg tamsulosin or 5 mg tadalafil daily for 30 days or until calculus clearance, whichever was earlier. Results There was no difference in the primary outcome, namely, calculus expulsion rate at 30 days (tamsulosin vs tadalafil, n (%) 99 [81.1%] vs 98 [80.3%] respectively, 95% confidence interval = 0.8% [-9.0, 10.7], P = 0.874). Similarly, a lack of difference was also noted in the secondary outcome, number of days to expulsion (tamsulosin vs tadalafil, geometric mean [SD] 13.59 [2.39] vs 13.74 [2.39] respectively, P = 0.928). Four patients discontinued the drug due to adverse drug reactions in the tadalafil group. Conclusions Low-dose tadalafil is not superior to tamsulosin in improving calculus expulsion when used as an adjunct to shockwave lithotripsy. In this study, we also noted that tadalafil was less tolerated.