As has been described more than once on this blog, the evidence favoring use of tamsulosin for renal colic has been grossly overstated. The vast majority of the trial evidence collated by the Cochrane Review has been distorted by small trials and those biased by pharmaceutical manufacturers. Every time a reasonably-designed randomized-controlled trial has been performed, the magnitude of effect has been dramatically lower – or non-existent.
This, the STONE trial, included 512 patients with ureteral stones of fewer than 9mm in greatest diameter. Split into a single-center phase with patient-reported passage, and a multi-center phase with CT follow-up for passage, there were no clear advantages to tamsulosin. Of all the outcomes compared, both passage and surrogates for stone-related disability, there were no differences except one – in the CT follow-up phase, tamsulosin displayed a 6% absolute advantage in stone passage. Absent other correlated patient-oriented outcomes, it is reasonable to consider this as a chance finding – or, at least, of inadequate effect size to reliably affect clinical practice.
Considering these results generalize to the vast majority of symptomatic stones, if you’ve still been prescribing tamsulosin routinely, it is time for a rethink.
“Effect of Tamsulosin on Passage of Symptomatic Ureteral Stones”
The accompanying editorial makes a case for tamsulosin in > 5 mm stones.
It underlines the fact that 3/4 of the stones in this recent paper were ≤ 4 mm
By the way , there seems to be a mess up in the results report.
Don’t you think there is something weird ? Or should iI take an MMS test ?
here is the text (free access ) :
“history of previous urinary stone (99.0%; 48.7% in the tamsulosin group vs 52.6% in the placebo group; P = .35), urinary stone size (<5 mm; 56.4% in the tamsulosin group vs 51.7% in the placebo group; P = .45), and urinary stone location (upper ureter, 41.8% in the tamsulosin group vs 29.4% in the placebo group; P = .17) (99.0% in the tamsulosin group vs 98.2% in the placebo group; P = .67)."
I agree their proportions are confusingly stated, reported of the greater whole with stone passage rather than the specific subgroup.
I agree the numbers are small in this study for stones ≥5mm; failing to show a difference contributes to a post-test likelihood of only a small positive effect size, if any, in the context of the prior literature.
All these subgroups are “interesting” – though, generalizing them to the population we see in the ED or clinic and diagnose without CT, is virtually impossible.
Also worth noting this abstract, manuscript probably in revisions somewhere like the BMJ:
https://www.researchgate.net/publication/323807547_Medically_expulsive_therapy_MET_has_no_benefit_in_improving_spontaneous_stone_passage_SSP_in_patients_presenting_with_acute_ureteric_colic_Results_from_the_MIMIC_study
In my opinion, the wrong conclusion is being drawn in these studies and the authors are doing patients a disservice. A recent Cochrane Review on the subject highlights the key points:
1. There is evidence alpha blockers both increase the rate and hasten the time to expulsion for stones that are > 4-5 mm.
2. Serious side effects of these agents happen rarely.
Recent trials including this study and the Lancet study a few years ago include all stone sizes and locations; however, the original work on this issue a decade ago included average stone sizes of 6-7 mm and distal ureteral stones only. Furthermore, the large scale trial from China published last year in European Urology again showed a benefit for distal stones and a low rate of adverse events with these drugs.
Furthermore, if we throw this therapy away, what options are patients left with? Observation or surgical intervention. Keeping MET as a viable option for distal stones that are > 4-5 mm in size does patients a service and the take home message from several recent studies is misleading and sending us back 15-20 years in our treatment paradigm for ureteral stones.
No disagreement re: low incidence of side effects.
Some of the “failure to find a difference” relates to statistical power, and each individual study shows some subgroup with benefit.
But, the main point to be made – modern, well-done trials find smaller and less consistent signals of benefit. It’s absolutely reasonable to offer these to patients with larger stones – just with the humility to admit the chance the medication will help is quite low.