Intravenous Magnesium Sulfate for Pain Management in Patients with Acute Renal Colic; a Randomized Clinical Trial

INTRODUCTION: It seems that magnesium (Mg) sulfate can be helpful in controlling the acute pain caused by the stone passing from the ureter by reducing ureter smooth muscle contractions. The present study has been designed with the aim of assessing the role of Mg sulfate in controlling the renal colic pain in emergency department (ED). METHODS: This double blind randomized clinical trial was performed on 18 to 60 year-old patients with acute renal colic presenting to the ED of a teaching hospital during 1 year. Patients were allocated to one of the 2 groups receiving either IV morphine or IV Mg sulfate using block randomization method and were then compared regarding pain control characteristics and probable side effects. RESULTS: 90 patients with the mean age of 37.34 ± 12.10 (18 – 60) years were divided into 2 equal groups. The 2 groups were in a similar condition regarding mean age (p = 0.168), sex distribution (p = 0.267), underlying disease (p = 0.414) and alcohol and drug abuse (p = 0.524). Mean pain scores of the patients based on VAS were not significantly different between the 2 groups on admission and 20, 30, 60, 120, and 180 minutes after drug administration. Success rate in reducing the pain by at least 3 points on VAS was equal and 91.1% for both groups on the 20(th) minute and reached 100% on the 30(th) minute for both groups. The number of cases that were pain-free on the 20(th) minute was significantly higher in the morphine groups (31 versus 16 patients, p = 0.004). However, on the 30(th) minute both groups experienced a similar condition in this regard (39 versus 29, p = 0.063). None of the patients in the 2 groups experienced the studied side effects. CONCLUSION: It seems that Mg sulfate, as a muscle relaxant agent, can be considered as a safe adjunct medication in controlling the pain of renal colic patients in the ED.