Ureteric (renal) colic is a common, painful condition encountered in the Emergency Department (ED). Sustained contraction of smooth muscle in the ureter as a kidney stone passes the length of the ureter leads to pain. The majority of stones will pass spontaneously (i.e. without urologic intervention). For over a decade, calcium channel blockers (i.e. nifedipine) and, more commonly, alpha adrenoreceptor antagonists (i.e. tamsulosin) have been employed in the treatment of ureteric colic for their potential ability to increase stone passage, reduce pain medication use and reduce urologic interventions. These interventions were mostly based on poor methodologic studies and meta-analyses of these flawed studies. A number of randomized trials performed over the last 6 years have not been as supportive. However, these studies were small and had flaws of their own. The question of whether medical expulsion therapy (MET) is beneficial remains.
Is MET (either nifedipine or tamsulosin) effective in increasing the spontaneous stone passage rate at 4 weeks.
Adults aged 18-65 with a single kidney stone < 10 mm identified by CT or KUB
Tamsulosin (400 mcg) or nifedipine (30 mg) daily
Primary: Need for urologic intervention to facilitate stone passage at 4 weeks after randomization
Multicenter, randomized, double-blind, placebo-controlled trial
Patients requiring immediate intervention, an estimated GFR < 20 ml/min and those already taking or unable to take tamsulosin or nifedipine.
- Primary endpoint: Placebo (20%) vs. Tamsulosin (19%) vs. Nifedipine (20%)
- No statistically significant difference between the three groups
- Lost to follow up: 14 patients (1.2%)
- MET was found to be beneficial in passage rate of lower ureteral tract stones (86% vs. 82%) but this was a not a prior specified subgroup analysis
- 1167 patients randomized with 1136 (97%) included in the primary analysis
- Power analysis: 90% power to detect a 10% difference between treatment groups
- 25% of stones were > 5 mm in size
- Large study with excellent methods
- True patient centered outcome (need for urologic intervention to facilitate stone passage)
- Excellent follow up (only 1.2% lost)
- Multicenter study
- Broad inclusion criteria
- Stone passage not documented, only absence of further intervention
- Only 25% of stones were large (> 5 mm)
“Tamsulosin 400 μg and nifedipine 30 mg are not effective at decreasing the need for further treatment to achieve stone clearance in 4 weeks for patients with expectantly managed ureteric colic.”
MET does not appear to facilitate the passage of kidney stones and should not empirically be used in most patients with ureteric colic.
Potential Impact To Current Practice
Significant. In many hospitals, use of MET is standard care for patients with ureteric colic. This well-done trial gives excellent evidence that this should not be part of standard treatment.
The majority of patients presenting with ureteric colic do not require treatment with either tamsulosin or nifedipine. Care should center on pain relief, ruling out concomitant infection and expectant management.
EM Lit of Note: Finally, an End to Tamsulosin for Renal Colic?