Tehran University of Medical Sciences Frontiers in Emergency Medicine 2717-3593 2 1 2017 12 04 e2 e2 Leyla Nasehi Department of Radiology, Cleveland Clinic Foundation; OH, USA. Reza Taslimi Department of Gastroenterology, Imam-Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. Ahmadreza Dehpour Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Javad Seyedhosseini Department of Emergency Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2017 10 07 2017 12 04 Introduction: Renal colic is caused by colicky spasms of ureters. As has been shown in previous experiments, glycerol trinitrate (TNG) can inhibit these muscular spasms. Objective: This study was performed to assess the pain relieving effect of TNG among patients referred due to renal colic pain to the emergency department (ED). Methods: This study is a randomized, placebo-controlled study on 60 patients with renal colic who were referred to the ED, who were diagnosed clinically to have renal colic, and their pain was more than 5 based on a visual analogue scale (VAS). The patient's pain was recorded at the moment of clinical diagnosis, and each one received one capsule, either 0.4 mg TNG or placebo, plus a 100 mg indomethacin suppository. The pain score was re-assessed after 5 and 30 min. The values were recorded and compared using SPSS-16 software. Results: Sixty patients with a mean age of 35.75 ± 11.99 years were enrolled (73.3% male). Patients in the two groups were matched for age (p = 0.290), sex (p = 0.559), and the presence of microscopic hematuria (p = 0.292). Pain relief from the start point until the end of the intervention was statistical different in all studied patients (p < 0.05); but the comparison between the two groups showed no significant difference in this regard (p = 0.440). Conclusion: It is likely that adding TNG to an indomethacin suppository had no significant effects on better pain management of patients referred with renal colic to the ED. https://fem.tums.ac.ir/index.php/fem/article/view/3 https://fem.tums.ac.ir/index.php/fem/article/download/3/34