From the Guidelines
Alpha blockers are the preferred agents for medical expulsive therapy (MET) in patients with ureteral stones, with a statistically significant 29% increase in stone passage rates compared to control patients. The use of alpha blockers, such as tamsulosin, terazosin, and doxazosin, has been shown to facilitate ureteral stone passage and reduce stone-passage time and pain 1. These medications work by relaxing the smooth muscles in the ureter, which helps to reduce pain and allows the stone to pass more easily through the urinary tract.
Some key points to consider when using alpha blockers for MET include:
- Tamsulosin is the most common alpha blocker utilized in these studies, but other alpha blockers such as terazosin and doxazosin have also been shown to be effective 1
- The beneficial effects of these drugs are likely attributed to ureteral smooth muscle relaxation mediated through either inhibition of calcium channel pumps or alpha-1 receptor blockade 1
- Alpha blocker therapy typically increases stone passage rates by 29% and reduces the time to stone passage compared to standard care alone 1
- Patients should be advised to take alpha blockers with plenty of water and may continue their normal pain management regimen while using them
- Common side effects include dizziness, headache, retrograde ejaculation in men, and orthostatic hypotension (a drop in blood pressure when standing up)
It is essential to note that the evidence supports the use of alpha blockers as the preferred agents for MET, and tamsulosin has been the most common alpha blocker utilized in these studies. However, other alpha blockers such as terazosin and doxazosin may also be effective 1.
From the Research
Treatment of Alpha Blockers for Kidney Stones
- The use of alpha-blockers as medical expulsive therapy for ureteral stones has been studied in several trials 2, 3, 4, 5, 6.
- Alpha-blockers have been shown to increase stone clearance rates for ureteral stones ≤10 mm treated without lithotripsy 2.
- For ureteral or renal stones treated with lithotripsy, alpha-blockers have been found to be beneficial in increasing stone clearance rates 2, 3, 4, 6.
- The efficacy of alpha-blockers may vary with stone size, with better results for stones 10-20 mm in size 5, 6.
- Tamsulosin is the most commonly studied alpha-blocker and has been shown to be effective in enhancing stone clearance rates 3, 4, 5, 6.
- Adverse events associated with alpha-blockers are generally mild and include dizziness, headache, and hypotension 3, 4, 6.
- The number needed to treat with alpha-blockers to achieve stone clearance has been estimated to be around 2-3 6.
- Alpha-blockers may also reduce the need for hospitalization and surgical intervention 5.
- The use of alpha-blockers as medical expulsive therapy for ureteral stones is supported by the evidence, but the decision to use them should be made on a case-by-case basis, taking into account the individual patient's characteristics and medical history 2, 5.