NEW YORK (Reuters Health) – Urologists from China report that the alpha-adrenergic receptor antagonist tamsulosin is a good first-line drug for outpatient medical expulsive therapy (MET) in patients with distal ureteric stones with renal colic.

They’ve found it to be significantly better than the calcium channel blocker nifedipine in relieving renal colic and promoting ureteric stone passage, findings that agree with results of previous clinical trials, the clinicians note in the November 17 online issue of BJU International.

MET for ureteric stones using alpha-adrenergic antagonists, calcium channel blockers and anti-edema agents has “gained extensive attention,” Dr. Zhangqun Ye, from Tongji Hospital in Wuhan and colleagues note in their article.

In most studies, MET using one of these agents was shown to facilitate the expulsion of ureteric stones and relieve renal colic. However, a number of design issues, including small size, limit the results of these studies.

To investigate further, Dr. Ye and colleagues conducted a large, prospective, randomized study involving 3,189 patients from 10 centers in China in which they compared the efficacy of the tamsulosin to that of nifedipine in MET for distal ureteric stones with renal colic.

The groups were well matched in terms of age, gender, stone size and stone location. The median stone size in the entire study population was 5.7 millimeters.

During a maximum of 4 weeks follow up, stone expulsion rates were greater in the tamsulosin group than in the nifedipine group (P < 0.01). The spontaneous stone expulsion rates were 95.86% and 73.51%, respectively. It also took significantly less time, on average, to expel stones with tamsulosin than with nifedipine (78.35 hours vs 137.93 hours; P < 0.01). Tamsulosin users were also less apt to use pain relief therapy (1.53% vs 4.84%) and, when they did use analgesics (diclofenac), they used less of it (52.35 mg vs 109.33 mg; P < 0.01 for both). There were no statistically significant between-group differences in the incidence of side effects (5.62% with tamsulosin vs 6.16% with nifedipine). Overall, side effects were generally mild and none of the patients withdrew from the study because of side effects caused by the medications, Dr. Ye and colleagues note. MET is a noninvasive therapeutic option for distal ureteric calculi, alongside watchful waiting, extracorporeal shockwave lithotripsy, ureteroscopic lithotripsy and ureterolithotomy, the investigators say. Based on their clinical experience, tamsulosin “can be recommended as first-line drug for MET in the outpatient setting,” they conclude. The study was supported by Astellas Pharmaceutical, which makes tamsulosin. BJU Int 2010.