Ketamine May be Safer, More Effective Than Opioids for Patients With Renal Colic

In patients with renal colic, treatment with ketamine yielded longer-lasting relief than opioids and had a much better safety profile.

Compared with opioids, ketamine treatment is safer and provides longer-lasting pain relief for patients with renal colic, according a study published in Pain and Therapy.

Researchers conducted a systematic review and meta-analysis of published randomized controlled trials (RCTs) to compare the use of ketamine vs opioids for the treatment of renal colic, following the latest Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines. The databases searched included PubMed, EMBASE, Cochrane Library, and Web of Science.

The primary outcome was a measurement of patient-reported pain scores 5, 15, 30, and 60 minutes after drug administration, and the secondary outcome was on identifying side effects.

Compared to opioids, the use of ketamine produces more persistent relief in patients with renal colic and has a much better safety profile.

In their evaluation of the 5 RCTs selected for final analysis (which enrolled a total of 690 participants with renal colic), the authors found that patients receiving ketamine vs opioids reported similar pain intensities at 5 minutes (MD, −0.40; 95% CI, −1.82 to 1.01; P =.57), 15 minutes (MD, −0.15; 95% CI, −0.82 to −0.52; P =.67), and 30 minutes (MD, 0.38; 95% CI, −0.25 to 1.01; P =.24) after treatment. However, at 60 minutes post-administration, ketamine yielded a better pain score than opioids (MD, −0.12; 95% CI, −0.22 to −0.02; P =.02).

In addition, the ketamine group had a significantly lower incidence of hypotension, with an odds ratio of 0.08 (95% CI, 0.01 to 0.65; P =.02). There was no statistically significant difference between the 2 groups in terms of nausea, vomiting, dizziness, and blood pressure.

This study was limited by the possibility of bias in the studies reviewed. For example, ketamine was administered intravenously in 1 study and intranasally in 4 studies. Further, all 5 RCTs were conducted in Iran, which may limit the generalizability of the meta-analysis findings.

The authors concluded, “Compared to opioids, the use of ketamine produces more persistent relief in patients with renal colic and has a much better safety profile.”


Zhang D, Liang P, Xia B, Zhang X, Hu X. Efficacy and safety of ketamine versus opiates in the treatment of patients with renal colic: a systematic review and meta-analysis. Pain Ther. Published online June 7, 2023. doi:10.1007/s40122-023-00530-0