of choice in 13 out of 16 randomized controlled trials. As
discussed earlier, there also appears to be a theoretical advantage
in using tamsulosin, owing to its specificity for the
α-1A and α-1D adrenergic receptor subtypes. Similarly, the
reviews also suggest that nifedipine should be the calciumchannel
blocker of choice. The eight randomized controlled
trials identified in Singh [17] and Hollingsworth [18] that
examined the efficacy of calcium-channel blockers all used
nifedipine. Nifedipine is also in widespread use in the UK’s
National Health Service (NHS) for other indications.
The main anticipated risk to participants is that they
suffer an adverse reaction to the trial medication.
Treatment with α-blocker or nifedipine is associated
with a small risk of adverse effects. In the report by
Singh and colleagues [18], the incidence of mild adverse
effects was 4% with α-blocker and 15% with nifedipine.
However, both trial drugs are in common use
for different indications, and the undesirable effects
(such as postural hypotension and tachycardia) are well
recognized. Patients with a contraindication to either
drug will not be included in the trial. The off-label use of
tamsulosin in women is well documented in the literature
and there have not been any reports of any specific adverse
reactions to treatment in female participants. However, the
risks of tamsulosin use during pregnancy are unknown and
nifedipine is contraindicated during pregnancy. Two suitable
‘highly effective’ forms of contraception must be used
by women of childbearing potential entering the trial.
The aim of this trial is to determine the clinical effectiveness
and cost-effectiveness of the use of tamsulosin and nifedipine
in the management of symptomatic urinary stones.
The potential benefits to participants are that the pain and
discomfort caused by their ureteric stones will be relieved
sooner and the avoidance of additional treatment (such as
ureteroscopy or extracorporeal shock wave lithotripsy) will
be reduced by 25% to 45%.
In the context of all trial groups receiving standard supportive
care, two pragmatic comparisons will be made in
evaluating MET for the facilitation of ureteric stone passage: