Nonsteroidal anti-inflammatory drugs (NSAIDs) and non-opioids for acute renal colic

Renal colic is acute pain caused by urinary stones. The prevalence of urinary stones is between 10% and 15% in the United States, making renal colic one of the common reasons for urgent urological care. The pain is usually severe and the first step in the management is adequate analgesia. Many different classes of medications have been used in this regard including non-steroidal anti-inflammatory drugs and narcotics.

The aim of this review was to assess benefits and harms of different NSAIDs and non-opioids in the treatment of adult patients with acute renal colic and if possible to determine which medication (or class of medications) are more appropriate for this purpose. Clinically relevant outcomes such as efficacy of pain relief, time to pain relief, recurrence of pain, need for rescue medication and side effects were explored.

We searched the Cochrane Renal Group's Specialised Register (to 27 November 2014) through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

Only randomised or quasi randomised studies were included. Other inclusion criteria included adult patients with a clinical diagnosis of renal colic due to urolithiasis, at least one treatment arm included a non-narcotic analgesic compared to placebo or another non-narcotic drug, and reporting of pain outcome or medication adverse effect. Patient-rated pain by a validated tool, time to relief, need for rescue medication and pain recurrence constituted the outcomes of interest. Any adverse effects (minor or major) reported in the studies were included.

Abstracts were reviewed by at least two authors independently. Papers meeting the inclusion criteria were fully reviewed and relevant data were recorded in a standardized Cochrane Renal Group data collection form. For dichotomous outcomes relative risks and 95% confidence intervals were calculated. For continuous outcomes the weighted mean difference was estimated. Both fixed and random models were used for meta-analysis. We assessed the analgesic effects using four different outcome variables: patient-reported pain relief using a visual analogue scale (VAS); proportion of patients with at least 50% reduction in pain; need for rescue medication; and pain recurrence. Heterogeneity was assessed using the I² test.

A total of 50 studies (5734 participants) were included in this review and 37 studies (4483 participants) contributed to our meta-analyses. Selection bias was low in 34% of the studies or unclear in 66%; performance bias was low in 74%, high in 14% and unclear in 12%; attrition bias was low in 82% and high in 18%; selective reporting bias low in 92% of the studies; and other biases (industry funding) was high in 4%, unclear in 18% and low in 78%.Patient-reported pain (VAS) results varied widely with high heterogeneity observed. For those comparisons which could be pooled we observed the following: NSAIDs significantly reduced pain compared to antispasmodics (5 studies, 303 participants: MD -12.97, 95% CI -21.80 to - 4.14; I² = 74%) and combination therapy of NSAIDs plus antispasmodics was significantly more effective in pain control than NSAID alone (2 studies, 310 participants: MD -1.99, 95% CI -2.58 to -1.40; I² = 0%).NSAIDs were significantly more effective than placebo in reducing pain by 50% within the first hour (3 studies, 197 participants: RR 2.28, 95% CI 1.47 to 3.51; I² = 15%). Indomethacin was found to be less effective than other NSAIDs (4 studies, 412 participants: RR 1.27, 95% CI 1.01 to 1.60; I² = 55%). NSAIDs were significantly more effective than hyoscine in pain reduction (5 comparisons, 196 participants: RR 2.44, 95% CI 1.61 to 3.70; I² = 28%). The combination of NSAIDs and antispasmodics was not superior to NSAIDs only (9 comparisons, 906 participants: RR 1.00, 95% CI 0.89 to 1.13; I² = 59%). The results were mixed when NSAIDs were compared to other non-opioid medications.When the need for rescue medication was evaluated, Patients receiving NSAIDs were significantly less likely to require rescue medicine than those receiving placebo (4 comparisons, 180 participants: RR 0.35, 95% CI 0.20 to 0.60; I² = 24%) and NSAIDs were more effective than antispasmodics (4 studies, 299 participants: RR 0.34, 95% CI 0.14 to 0.84; I² = 65%). Combination of NSAIDs and antispasmodics was not superior to NSAIDs (7 comparisons, 589 participants: RR 0.99, 95% CI 0.62 to 1.57; I² = 10%). Indomethacin was less effective than other NSAIDs (4 studies, 517 participants: RR 1.36, 95% CI 0.96 to 1.94; I² = 14%) except for lysine acetyl salicylate (RR 0.15, 95% CI 0.04 to 0.65).Pain recurrence was reported by only three studies which could not be pooled: a higher proportion of patients treated with 75 mg diclofenac (IM) showed pain recurrence in the first 24 hours of follow-up compared to those treated with 40 mg piroxicam (IM) (60 participants: RR 0.05, 95% CI 0.00 to 0.81); no significant difference in pain recurrence at 72 hours was observed between piroxicam plus phloroglucinol and piroxicam plus placebo groups (253 participants: RR 2.52, 95% CI 0.15 to12.75); and there was no significant difference in pain recurrence within 72 hours of discharge between IM piroxicam and IV paracetamol (82 participants: RR 1.00, 95% CI 0.65 to 1.54).Side effects were presented inconsistently, but no major events were reported.

Although due to variability in studies (inclusion criteria, outcome variables and interventions) and the evidence is not of highest quality, we still believe that NSAIDs are an effective treatment for renal colic when compared to placebo or antispasmodics. The addition of antispasmodics to NSAIDS does not result in better pain control. Data on other types of non-opioid, non-NSAID medication was scarce.Major adverse effects are not reported in the literature for the use of NSAIDs for treatment of renal colic.