Acute renal colic from ureteral calculus
Review of: Teichman JMH. N Engl J Med 2004; 350:684-693 and comment in Acute Renal Colic by Miller DC and Wolf Jr JS. N Engl J Med 2004; 350:2422-2423
Recent studies describe the use of pharmacological treatment in order to facilitate spontaneous passage of ureteral stones, however, there is no consensus about the ultimate combination of drugs to be used. Corticosteroids modulate inflammation and oedema, misoprostol is a gastroprotective agent and a powerful prostaglandin E1 analogue and the calcium-channel blocker nifedipine has a spasmolytic effect. Not only corticosteroids display side-effects, nifedipine has been attributed with cardiovascular sideeffects including palpitations and hypotension.
In a letter to the Editor of the New England Journal of Medicine, Miller and Wolf write that, although TeichmanÅLs review of acute renal colic due to ureteral calculus (Feb 12 issue, 2004) was generally comprehensive, he failed to mention nifedipine in the medical treatment of patients with ureteral colic. Millar and Wolf claim that the merits of nifedipine are increasingly recognized by urologic authorities and that evidence-based medical management of ureteral stones should include nifedipine XL at a dosage of 30 mg once daily. They argue that a combination of nifedipine, corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs) was proven effective in three randomized controlled studies, when stone passage was included as one of the clinically relevant endpoints. Furthermore, Miller and Wolf excluded corticosteroids in their treatment regimen in order to minimize adverse pharmacologic effects.
A somewhat different opinion was given in TeichmanÅfs reply, who referred to one prospective randomized trial demonstrating that a combination of daily deflazacort (30 mg), nifedipine XL (30 mg), and misoprostol (200 É g twice daily) virtually eliminated the need for an NSAID (15 mg diclofenac per patient) and resulted in 79 percent of patients spontaneously passing (the) stone(s), as compared to 35 percent of patients in the diclofenac group (P<0.05). Teichman proposes that a reasonable combination therapy for stone-expulsion therapy may be a combination of a corticosteroid and nifedipine XL, with or without misoprostol, and an NSAID for breakthrough pain. Another interesting study, mentioned by Teichman, shows that tamsulosin (alphablocker) and deflazacort similarly improve stone-expulsion rates in a randomized, controlled trial involving patients with juxtavesical ureteral calculi.
In conclusion, several studies now favour pharmacologic treatment to enhance spontaneous stone passage in patients with distal ureteral stones for whom urgent surgical intervention is unnecessary. Additional prospective randomized clinical trials are needed to identify the ultimate combination of drugs to be used.
