Drugs help pass more ureteral stones

α-Antagonist studies

These 16 studies enrolled 1235 patients with distal ureteral stones. Mean stone size ranged from 4.3 to 7.8 mm. α-Antagonists improved the stone expulsion rate (RR= 1.59, 95% CI 1.44-1.75; NNT=3.3).

The mean time to expulsion of the stone ranged from 2.7 to 14.2 days and duration of therapy ranged from 1 to 7 weeks. In the 9 trials that reported the time to stone expulsion, the stone came out between 2 and 6 days earlier than the control groups.

Adverse effects were reported in 4% of patients receiving the active medication; most were mild.

Nifedipine studies

There were 686 patients in the 9 trials of nifedipine. The mean stone size was 3.9 to 12.8 mm. Some studies included stones in the more proximal as well as the distal ureter.

Nifedipine treatment increased the rate of stone expulsion (RR=1.5, 95% CI 1.34-1.68; NNT=3.9). Time to stone expulsion was shorter in 7 of the 9 studies.

Adverse effects were reported in 15% of the patients. Most of these were mild— nausea, vomiting, asthenia, and dyspepsia.

WHAT’S NEW: Strong evidence for use of medical therapy

The new findings from the Singh meta-analysis reviewed in this PURL supports physicians who have already adopted this practice and should encourage usage by those who have not yet done so.

Inpatients in academic medical centers

There is a growing trend to use tamsulosin to facilitate passage of ureteral stones. The University Health System Consortium (www.uhc.org) has complete clinical data on inpatients with ureteral stones, from 64 academic medical centers and teaching hospitals, between 2003 and 2007. We used this database to analyze trends in the use of tamsulosin in 4300 inpatients with ureteral stones (ICD 9 code 5921).

In 2003, only 3.3% of patients with a discharge diagnosis of ureteral stone received tamsulosin. In 2007, 34.1% of patients with ureteral stones discharged from these hospitals received tamsulosin, with similar rates of use when stratified by the specialty of the attending physician at discharge (family medicine, emergency medicine, internal medicine, urology) (FIGURE 1). We noted a wide range in the rate of adoption of this practice among academic medical centers: 48% in the centers with the highest rate of usage and 4.4% in the centers with the lowest rate.

FIGURE 1
% of inpatients in academic medical centers who received tamsulosin for ureteral stones, by year

Outpatients from a sample of US practices

The use of tamsulosin or nifedipine in outpatient practice was infrequent even 2 or 3 years ago. We used the National Ambulatory Medical Care Survey data (www.cdc.gov/nchs/about/major/ahcd/ahcd1.htm) from 2004 and 2005 (the most recent available), which provides a sample of all US outpatient practices. Only 7% of an estimated 1,345,000 patients diagnosed with ureteral stones were prescribed either tamsulosin or nifedipine, and urologists cared for most of those.

These unpublished data show that physicians in academic medical centers are increasingly adopting the practice of using tamsulosin or nifedipine for expulsion of ureteral stones, that urologists appear to be the first to begin using these medications in outpatients several years ago, and that this practice is being adopted actively in selected academic medical centers.