From the Guidelines
Flomax (Tamsulosin) is recommended for kidney stones to facilitate their passage, with a statistically significant 29% increase in stone passage compared to control patients. The use of alpha blockers, such as tamsulosin, has been shown to be effective in facilitating the spontaneous passage of ureteral stones, as demonstrated in a meta-analysis 1. This medication works by relaxing the smooth muscles in the ureter, which helps widen the urinary passage and allows stones to move through more easily. Some key points to consider when using Flomax for kidney stones include:
- The standard dose is 0.4mg taken once daily, preferably 30 minutes after the same meal each day
- The medication should be continued until the stone passes or for about 2-4 weeks
- Tamsulosin is most effective for stones located in the lower part of the ureter
- Common side effects include dizziness, headache, retrograde ejaculation in men, and orthostatic hypotension
- Patients should maintain adequate hydration (2-3 liters of water daily) and use pain medication as prescribed while taking Flomax
- It is essential to seek immediate medical attention if experiencing severe pain, fever, or inability to urinate, as these may indicate complications requiring urgent care, according to the 2007 guideline for the management of ureteral calculi 1.
From the Research
Efficacy of Flomax (Tamsulosin) for Kidney Stones
- The efficacy of tamsulosin in enhancing stone clearance in patients with renal stones 10-24 millimeters in diameter has been supported by evidence 2.
- A systematic review and meta-analysis of randomized controlled trials found that tamsulosin was associated with a higher stone expulsion rate, shorter stone expulsion time, and fewer incidences of requiring subsequent intervention 3.
- Tamsulosin has been shown to be effective in patients with ureteral stones greater than 5 mm in size, with a significant benefit in stone expulsion rate observed in this subgroup 3.
Safety and Tolerability
- Tamsulosin has been reported to be well tolerated, with a low incidence of side effects 2, 3.
- Adverse events were more frequent in the nifedipine group compared to the tamsulosin group in one study 4.
- Tamsulosin has been found to be a safe and effective medical expulsive therapy choice for ureteral stones, with a lower incidence of adverse effects compared to calcium channel blockers 5.
Comparison with Other Treatments
- Tamsulosin has been compared to nifedipine in one study, which found that both drugs increased the stone-free rate after extracorporeal shock wave lithotripsy, but nifedipine was associated with more adverse effects 4.
- A systematic review and meta-analysis found that tamsulosin had a higher stone expulsion rate compared to calcium channel blockers 5.
Stone Size and Location
- The efficacy of tamsulosin has been found to be greater for stones 10-20 mm in size, with a significant benefit in stone expulsion rate observed in this subgroup 4.
- Tamsulosin has been shown to be effective in patients with distal ureteral stones, with a higher stone expulsion rate observed in this subgroup 5.