Ningmitai capsule promotes calculi expulsion after RIRS for 10–20-mm upper urinary stones: a multicenter, prospective, randomized controlled trial

To evaluate the efficacy and safety of the use of Ningmitai capsule as an adjunctive stone expulsion therapy after RIRS. All patients were diagnosed with upper urinary tract calculi measuring 10–20 mm. The patients who successfully underwent RIRS were randomly assigned to the NMT capsule group (Ningmitai capsule, 1.52 g, three times daily) or the control group for 4 weeks based on the random number table method. The primary endpoints were the stone expulsion rate (SER) and stone-free rate (SFR). The average stone expulsion time (SET), average stone-free time (SFT) and complications were recorded. Between July 2, 2019, and December 17, 2020, 220 participants successfully underwent RIRS across 6 centers; 123 of them were randomized according to the exclusion criteria, and 102 (83%) were included in the primary analysis. The SERs on the 3rd, 7th, 14th and 28th days were significantly increased in the NMT capsule group compared with the control group (78.95% vs. 31.11%, 92.98% vs. 55.56%, 94.74% vs. 64.44%, 100% vs. 82.22%, respectively, p < 0.05). The SFRs on the 3rd and 7th days were not different (p > 0.05), while those on the 14th and 28th days were higher in the NMT capsule group (63.16% vs. 24.44% and 92.98% vs. 68.89%, p < 0.05). The average SET and average SFT of the NMT capsule group were remarkably shorter than those of the control group (p < 0.001). During the follow-up period, there were no significant differences in urine RBC counts between the two groups (p > 0.05). The urine WBC counts of the NMT capsule group were significantly lower than those of the control group on the 14(th) day (p = 0.011), but there was no difference on the 3rd, 7th or 28th day (p > 0.05). The analgesic aggregate of the NMT capsule group was also much lower (p = 0.037). There were no significant differences in adverse events (p > 0.05), and they improved significantly without sequelae. This study indicated that NMT capsules can significantly promote stone clearance and are more effective and safer for upper urinary calculi after RIRS. Trial registration Chinese Clinical Trial Registration No. ChiCTR1900024151. Date of registration June 28, 2019. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00240-021-01296-w.