Is there a role for antimuscarinics in renal colic? A randomized controlled trial.

PURPOSE We determined whether the addition of hyoscine butylbromide (Buscopan) reduces the amount of opioid analgesia required and the need for ongoing opioid analgesia in acute renal colic. MATERIALS AND METHODS Patients with a clinical diagnosis of acute renal colic were prospectively randomized to receive Buscopan or placebo in addition to morphine and intravenous fluids, with or without indomethacin. Observations and pain scores were recorded 15 every minutes during the first hour then hourly thereafter. Morphine was administered in 2.5 mg increments until pain relief was achieved. Recordings were ceased at 4 hours or on discharge from the emergency department, whichever occurred first. The diagnosis of renal colic was confirmed by computerized tomography. The dose of morphine (mg/kg) and the proportion of patients who required further morphine were compared between the 2 groups. RESULTS Of the 192 patients randomized, data were available for 178 on an intent to treat basis. A total of 85 patients received Buscopan while 93 received placebo in addition to standard therapy. Patients in the Buscopan group required a median of 0.12 mg/kg of morphine while those in the placebo group received a median of 0.11 mg/kg, and this difference was not significant (p =0.4). There was also no significant difference in the proportion of patients who required additional morphine, 33% in the Buscopan group and 38% in the placebo group (p =0.5). Subgroup analysis of the 138 patients with a confirmed stone also showed no difference between the groups. CONCLUSIONS There is no evidence that Buscopan reduces opioid requirements or the need for ongoing opioid analgesia in acute renal colic.