Investigating the Analgesic Effect of Sublingual Glycerol Trinitrate (GTN) Spray as an Alternative Treatment in Renal Colic Pain: A Triple-Blinded Randomized Controlled Trial

Renal colic, a severe pain caused by renal and urethral calculi, causes millions of patients to visit the emergency department (ED) worldwide each year. Based on international guidelines, NSAIDs are the first-line analgesics of choice for renal colic management. The second most preferred analgesic is opioids. NSAIDs and opioids have several complications and contraindications that limit their administration and necessitate the search for alternative treatments for renal colic pain. The present study aimed to assess the effect of sublingual Glycerol Trinitrate (GTN) spray, a smooth muscle-relaxing agent, on renal colic pain as an alternative treatment. In this triple-blinded randomized controlled trial, 94 patients with renal colic who visited the emergency department (ED) were included. The drug group included 48 patients who were administered sublingual GTN spray, and the placebo group consisted of 46 patients. After diagnosis, the patients' pain was assessed based on the Numeric Rating Scale (NRS), a 30-milligram dose of ketorolac was administered to all patients, and sublingual GTN/placebo spray was administrated. The pain was also recorded 5 min after spray administration. Again, 30 min after spray administration, the NRS was reassessed. 94 patients enrolled in this study, the mean age of the participants was 39.22±11.72, and 82 (87.23%) of them were male. Five minutes after GTN/placebo administration, The NRS in both groups decreased significantly compared with the NRS upon arrival (P<0.01). Furthermore, in both groups, the NRS measured at 30 minutes also decreased significantly from the NRS measured at 5 minutes (P<0.01). Nevertheless, the reduction in the NRS score between the drug and placebo groups was not significantly different (P=0.365). Our results showed no significant pain reduction with sublingual GTN spray in comparison with placebo; thus, sublingual GTN spray might not have considerable analgesic effects in patients with renal colic referred to the ED.