Treatment with tamsulosin does not improve expulsion of distal ureteric calculi but does reduce the need for analgesia, a study from Switzerland has found.

A hundred patients with single distal ureteric stones <7mm in diameter were randomised to receive 21 days of treatment with either tamsulosin or placebo. (Stones larger than this are extremely unlikely to pass spontaneously.) Of the original 100, 10 withdrew and were not included in data analysis, while eight discontinued, mainly because of uncontrollable pain, but were included in the final analysis. Thus 45 patients in each arm were analysed.

No significant difference in mean stone size was seen between the two arms (4.1mm in the tamsulosin arm vs 3.8mm in the placebo arm). There was no significant difference in stone expulsion rate between the two arms (86.7% in the tamsulosin arm vs 88.9% in the placebo arm). All 11 stones that failed to pass were in the distal ureter rather than at the vesico-ureteric junction.

Stone expulsion rate was significantly higher in both arms for stones <5mm – there was, however, no significant difference between the two treatment arms for these smaller stones or for those with larger stones >5mm.

Time to stone passage was shorter in the tamsulosin arm (7 days vs 10 days for placebo) but because of the small numbers in this trial this was not of statistical significance. Tamsulosin treatment was well tolerated, four patients had minor side-effects.

Interestingly, patients in the tamsulosin arm of the study reported significantly lower pain scores and analgesic requirements than those in the placebo arm.

For some time, alpha-blockers have been considered to aid the expulsion of distal ureteric calculi, and such medical expulsive therapy (MET) has become an option for patients trying to avoid more interventional procedures such as lithotripsy or ureteroscopy.

The use of alpha-blockers for MET has been studied extensively using randomised trials, but this trial is the first randomised, double blind, placebo-controlled trial to assess the efficacy of tamsulosin for this role.

The authors conclude that although expulsion rate was not improved by tamsulosin, patients may benefit from an analgesic effect and hence a reduced requirement for analgesics until stone expulsion.