BET 4: Alpha blockers v calcium blockers to increase spontaneous passage of renal calculi
A short cut review was carried out to establish the administration of an alpha-1 receptor antagonist or a calcium channel blocker would facilitate the most rapid and successful expulsion of a stone from a patient with uncomplicated renal colic. 597 articles were found using the reported search, of which five trials were selected as providing the best evidence to answer this question. The authors, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. It is concluded that in a patient with an uncomplicated ureteric calculus tamsulosin is more effective than nifedipine in promoting speedy and successful expulsion of the stone.
A 51 year old presents to A&E with loin pain and macroscopic haematuria and a diagnosis of renal calculi is made. The patient's pain is adequately controlled and the decision is discharge with Medical Expulsive Therapy (MET) – but you don't know whether to prescribe alpha-adrenergic antagonists or calcium channel blockers.⇓
In [adult patients with urinary calculi] is [treatment with alpha receptor blockers superior to treatment with calcium channel antagonists] at [increasing the speed and success of spontaneous stone passage]?
1. Ovid MEDLINE 1946 to Nov week 2 2012 and Embase 1980 to 2012 Week 46 via OVIDSP interface.
[adrenergic alpha antagonist.mp OR alpha blocker$.mp. OR tamsulosin.mp. OR flomax.mp. OR alfuzosin.mp. OR doxazosin.mp. OR terazosin.mp. OR silodosin.mp. OR calcium antagonist$.mp. calcium channel blocker.mp. OR nifedipine.mp. OR nimodipine.mp. OR amlodipine.mp. OR felodipine.mp.] AND [((renal.mp. OR urinary.mp. OR kidney$.mp. OR urological.mp.) AND (stones.mp or calcul$.mp)) OR urolithiasis.mp. OR nephrolithiasis.mp.] limited to English language and human and “therapy (maximises sensitivity)”
2. Cochrane Database of Systematic Reviews 2005 to June 2012
(stones OR calculus OR urolithiasis OR nephrolithiasis)
1. 597 studies were found in total: five papers were felt to be relevant to the three-part question.
2. One relevant review protocol was found, but no relevant completed reviews.
Medical Expulsion Therapy (MET) is becoming more commonplace as an effective means of managing uncomplicated renal stones. MET is thought to work by causing relaxation of the smooth muscle in the ureter wall. Both calcium antagonists and alpha adrenoceptor blockers appear to have beneficial effects compared with placebo. In all of the selected papers patients taking tamsulosin were more likely to pass a renal calculus and in the cases where expulsion did occur it happened more quickly than for the patients taking nifedipine. This is most noticeable in the study by Ye et al due to the large numbers involved and the very significant effect. Each of the studies excluded a variety of groups of patients with known allergies to the selected agents, diabetes, renal disease, hypertension etc so these factors would have to be taken into account in prescribing these agents. Although these effects are presumably dependent on the pharmacological class of these agents only tamsulosin and nifedipine have been specifically studied in these trials.
Clinical Bottom Line
In patients with renal colic due to uncomplicated ureteric calculi, administration of tamsulosin increases the likelihood of spontaneous expulsion of the stone and decreases the time taken for this to occur compared with nifedipine.
▸ Dellabella M, Milanese G, Muzzonnigro G. Randomized trial of the efficacy of tamsulosin, nifedipine and phloroglucinol in medical expulsive therapy for distal ureteral calculi. The Journal of Urology 2005;174:167–172.
▸ Keshvari M, Taghavi R. The effect of tamsulosin in facilitating of juxtavesical stones' passage. Medical Journal of Mashhad University of Medical Sciences 2006:48(90):425–430.
▸ Zhang M, Ding S, Lu J, et al. Comparison of tamsulosin with extracorporeal shock wave lithotripsy in treating distal urethral stones. Chinese Medical Journal 2009;122(7):798–801.
▸ Ye Z, Yang H, Li H, et al. A multicentre, prospective, randomized trial: comparative efficacy of tamsulosin and nifedipine in medical expulsive therapy for distal ureteric stones with renal colic. British Journal of Urology International 2010;108:276–279.