Urolithiasis is a disease that effects 12% of the population and its incidence is growing. In the US there are over 1.1 million visits annually to Emergency Departments for renal colic. The disease is extremely painful, often requiring large amounts of narcotic analgesia, and results in lost work days. Moreover, up to 30% of patients may eventually require lithotripsy or surgical removal of the stone. Currently there are no medical interventions other than analgesia which are offered to patients.

Based on encouraging results from several small European clinical studies, the researchers hypothesize that the administration of tamsulosin to patients with symptomatic urolithiasis will enhance stone passage, and reduce both the time to recovery and the need for surgical intervention or lithotripsy. The researchers will conduct a study by identifying and recruiting patients presenting with urolithiasis in the emergency departments of four institutions.

A total of 302 consenting subjects will be randomly assigned to one of two groups:

1. tamsulosin for a maximum of 28 days;
2. placebo for a maximum of 28 days.

In addition, both groups will receive standard analgesic therapy.

The study team, which will be blinded to treatment status, will monitor each subject's clinical progress and outcome. The primary objectives of this study are:

1. to determine if tamsulosin is effective, and
2. to evaluate the safety of the therapy.

The secondary objective is to identify the most appropriate clinical subgroup(s) for treatment.

If the therapeutic benefits observed in smaller clinical studies are replicated, administration of these medications should produce several benefits, including:

1. a reduction in time to pain free recovery and hence a more rapid return to employment;
2. decreased requirements for narcotic analgesia;
3. less need for urological out-patient clinic follow-up;
4. decreased need for surgical intervention or lithotripsy; and
5. substantial cost savings.

If this therapy is beneficial, it will represent a major advance in the treatment of urolithiasis. This objective is a major stated goal of the NIDDK Clinical Urology Program, which has a stated mission to improve the treatment of urolithiasis.

Kidney stones are a major public health issue, and one person in eight will be affected by the disease. If the hypothesis is verified, the researchers will provide the first medical therapy ever for this disease. This therapy, if effective, will reduce the amount of time a patient is off work because of the pain from the disease, and may also reduce the need for expensive and time-consuming surgical treatments.