Alpha-blocker may help patients clear large stones

Atlanta-Adjunctive treatment with the alpha-blocker tamsulosin (Flomax) improves stone clearance and significantly reduces ureteral colic following ureteroscopic laser lithotripsy, researchers reported at the AUA annual meeting.

Administration of tamsulosin after ureteroscopic laser lithotripsy resulted in a stone-free rate of almost 95% and an almost six-fold reduction in the incidence of ureteral colic.

"Tamsulosin significantly enhanced stone clearance following ureteroscopic laser lithotripsy, especially in those patients with larger stones," said Sanjay Razdan, MD, director of the Urology Center of Excellence at Jackson South Hospital in Miami. "We believe that alpha-1 adrenergic receptor blockade may have a potential role in improving the results of laser lithotripsy."

"In our practice, we utilize ureteroscopy and laser lithotripsy as the primary modality for treating large renal and ureteral calculi," Dr. Razdan said. "Even after the most meticulous procedure, a minority of patients with large renal and ureteric calculi have ureteral colic episodes and small stone fragments on follow-up studies."

Patients with large stones benefit

Dr. Razdan and colleagues evaluated the impact of adjuvant tamsulosin in 40 patients undergoing ureteroscopic laser lithotripsy for treatment of large (mean, 1.1 cm) renal or ureteral calculi.

Following lithotripsy, half the patients received tamsulosin, 0.4 mg, plus standard analgesia with acetaminophen plus codeine. The other 20 patients received only analgesia. Follow-up continued for 4 weeks.

The primary clinical endpoint was the stone-free rate at 4 weeks, as demonstrated by helical computerized tomography. The secondary endpoint was the number of ureteral colic episodes during the 4 weeks. One patient in each group was excluded from the final analysis, leaving a total of 38.

The tamsulosin group had a stone-free rate of 94.7% compared with 83.1% of patients who received only standard analgesia after lithotripsy. Although favoring tamsulosin, the difference did not achieve statistical significance. Dr. Razdan said patients with the largest stones derived the greatest benefit from adjuvant tamsulosin. Patients who received the alpha-blocker did have a significantly lower incidence of ureteral colic (4.3% vs. 23.4%, p=.001).

"Adjunctive treatment with tamsulosin after ureteroscopic laser lithotripsy for large renal and ureteric calculi improves the stone-free rate, as well as patients' quality of life," Dr. Razdan concluded. "To the best of our knowledge, this is the first study to show the efficacy of tamsulosin after ureteroscopic lithotripsy."

Analgesia requirements reduced

Another AUA report provided evidence that adjunctive tamsulosin improves the stone-free rate after ESWL for large calculi (6 to 24 mm). The study involved 58 patients who were randomized to receive tamsulosin, 0.4 mg, or placebo following ESWL. Treatment continued until stone clearance or for a maximum of 30 days. Patients were allowed analgesia on demand in the form of combination preparation of dextropropoxyphene (Darvon), 65 mg, and acetaminophen, 400 mg, reported Antony Devasia, MD, a urologist at Christian Medical College in Vellore, India.

Patients treated with tamsulosin had a significantly higher rate of stone clearance (96.55% vs. 79.31%, p=.019). Stratification of patients by stone size revealed an advantage in stone clearance favoring tamsulosin in patients with 6- to 10-mm stones (100% vs. 88.23%, NS) and significant improvement in clearance of stones 11 to 24 mm in size (93.33% vs. 66.67%, p=.02).

Treatment with the alpha-blocker also reduced analgesia requirements, reflected by a median number of doses of two in the control group versus one in the tamsulosin group (NS). Five patients in the control group required hospitalization for pain relief, whereas one did so in the tamsulosin group. Steinstrasse occurred in 10 patients in the tamsulosin group and resolved spontaneously in all cases, whereas two of eight patients in the control group required intervention. The only adverse event reported in the study was one case of mild dizziness in a patient receiving tamsulosin.