When alpha-blockers may be helpful for kidney stones

Most stones smaller than a pencil eraser (5 mm) pass on their own. But new evidence suggests that alpha-blockers are helpful for larger stones from 5.

The controversy continues over whether alpha-blockers facilitate the passage of kidney stones. Tamsulosin or other alpha-blockers are commonly used to relax the ureters to help pass renal stones, but the evidence is conflicting. Low quality studies have shown an increased passage of kidney stones with doxazosin, terazosin, alfuzosin, and silodosin. Terazosin and doxazosin were shown to be equal in effects to tamsulosin in a small study, suggesting a possible class effect. However, these older alpha-blockers are generally associated with more adverse effects (e.g., dizziness, hypotension) than the newer alpha-blockers.

That's probably because stone size matters. Most stones smaller than a pencil eraser (5 mm) pass on their own. But new evidence suggests that alpha-blockers are helpful for larger stones from 5 mm up to the size of a plain M&M's candy (10 mm).

About one more in 5 patients will pass these larger stones and stones may pass a few days faster when an alpha-blocker is used for 4 weeks compared to placebo. Explain that patients with larger stones or stones that don't pass may need lithotripsy or other procedures to crush or remove the stone. Recommend scheduled NSAIDs for pain. They decrease ureteral spasms and work at least as well as opioids. In fact, NSAIDs are better than opioids at reducing the need for rescue pain medications and hospitalizations.

REFERENCES

Furyk, J.S., Chu, K., Banks, C., Greenslade, J., Keijzers, G., Thom, O., Torpie, T., Dux, C. and Narula, R. (2016). Distal Ureteric Stones and Tamsulosin: A Double-Blind, Placebo-Controlled, Randomized, Multicenter Trial. Annals of Emergency Medicine, [online] 67(1), pp.86–95.e2. Available at: https://pubmed.ncbi.nlm.nih.gov/26194935
Wang, R.C., Smith-Bindman, R., Whitaker, E., Neilson, J., Allen, I.E., Stoller, M.L. and Fahimi, J. (2017). Effect of Tamsulosin on Stone Passage for Ureteral Stones: A Systematic Review and Meta-analysis. Annals of Emergency Medicine, 69(3), pp.353-361.e3
Wang, R.C. (2016). Managing Urolithiasis. Annals of Emergency Medicine, [online] 67(4), pp.449–454. Available at: https://pubmed.ncbi.nlm.nih.gov/26616536