For adult patients experiencing the pain of renal colic on presentation to the emergency department (ED), intramuscular non-steroidal anti-inflammatory drugs offer the most effective sustained analgesia and also carry fewer side effects. This according to a double-blind, multigroup, randomized controlled trial of 1,645 adult participants aged 18 to 65 years with moderate to severe renal colic randomly included in the intention-to-treat analysis (547 in the diclofenac group, 548 in the paracetamol group, and 549 in the morphine group). Primary outcome was the proportion of participants achieving at least 50% reduction in initial pain scored at 30 minutes after analgesia. Researchers found:

• Primary outcome was achieved in 371 (68%) patients in the diclofenac group, 364 (66%) in the paracetamol group, and 335 (61%) in the morphine group in the intention-to-treat population.

• Compared to morphine, diclofenac was significantly more effective in achieving the primary outcome (OR=1.35), whereas no difference was detected in the effectiveness of morphine vs intravenous paracetamol (OR=1.26).

• In the per-protocol population, diclofenac (OR=1.49) and paracetamol (OR=1.40) were more effective than morphine in achieving primary outcome.

• Acute adverse events occurred in 19 (3%) of patients treated with morphine.

Citation: Pathan SA, Mitra B, Straney LD, et al. Delivering safe and effective analgesia for management of renal colic in the emergency department: a double-blind, multigroup, randomised controlled trial. Lancet. 2016;387:1999-2007. doi:http://dx.doi.org/10.1016/S0140-6736(16)00652-8.

Commentary: This study strongly supports the use of a parenteral NSAID for acute relief of pain in patients with kidney stones. At a time where there is a strong nationwide push to limit the use of opioid analgesics due to increasing problems with abuse, blinded comparative data on the efficacy of non-opioid treatments of pain allow us as clinicians to preferentially choose NSAIDs, even for the treatment of severe acute pain. —Neil Skolnik, MD