Adjuvant Drugs May Aid Clearance of Some Stones

Adjuvant use of tamsulosin or nifedipine after extracorporeal shock wave lithotripsy (SWL) improves stone free rates in patients treated for non-lower pole renal stones 10-20 mm in diameter, Brazilian researchers reported at the American Urological Association 2011 annual meeting.

In a double-blind study, Fabio Vicentini, MD, and colleagues at the University of São Paulo randomly assigned 136 with radioopaque non-lower pole kidney stones to receive daily treatments of 0.4 mg tamsulosin, 20 mg nifedipine, or placebo for up to 30 days after a single session of SWL. Patients were considered successfully treated if they no radiographic evidence of stones or they were asymptomatic with stone fragments 4 mm or less in size at any time during weekly follow-up.

The success rate was 60.5% in the tamsulosin arm, 48.6% in the nifedipine arm, and 36.8% in the placebo group, according to data in the researchers' poster presentation. The differences among the study arms were not statistically significant.

Among patients with 10-20 mm stones, however, those in the tamsulosin and nifedipine had significantly higher success rates (61.9% and 60%, respectively) than placebo recipients (26.1%). The study revealed no significant differences in stone clearance among patients with stones 5-9 mm in size.

Compared with placebo, adverse events rates were significantly higher with nifedipine than placebo (28.5% vs. 2.6%), but not with tamsulosin.

The three treatment arms were similar with respect to pain intensity and time to clearance.