POEMs

Low-Dose Morphine Less Effective Than Diclofenac or Acetaminophen for Renal Colic

 

Am Fam Physician. 2016 Oct 15;94(8):665.

Clinical Question

Which analgesics are most effective in providing significant pain relief in patients who are passing kidney stones in the emergency department?

Bottom Line

This is a good example of how a well-done study can lead to erroneous conclusions. The comparator most likely to be effective here—titrated morphine—was used at a low dose and found to be less effective than intramuscular diclofenac or intravenous paracetamol (acetaminophen). (Level of Evidence = 1b)

Synopsis

These authors randomly assigned more than 1,600 patients who presented to an emergency department with suspected kidney stones and pain severity of at least 4 out of 10 to receive 75 mg of intramuscular diclofenac (n = 548), 1 g of intravenous paracetamol (n = 548), or 0.1 mg per kg of intravenous morphine (n = 549). All patients had intravenous lines started and received intravenous or intramuscular placebo (each patient received one active injection and two placebo injections). They did not give any intravenous fluids until 30 minutes after the initial treatment and then only at the discretion of the treating physician. Approximately 80% of the patients in each group had a confirmed stone, and approximately 3% had no imaging performed.

After 30 minutes, nearly two-thirds of the patients in each group experienced at least a 50% reduction in their pain intensity (68%, 66%, and 61%, respectively; P = .04). The authors report that 3% of morphine-treated patients experienced adverse events compared with 1% with each of the other treatments. What happened after the first 30 minutes? The median pain score for each group at 90 minutes was 0. The median time to a pain score of less than 2 out of 10 was 60 minutes, regardless of treatment. Approximately 10% of patients who received diclofenac required rescue analgesia compared with approximately 20% of patients who received the other analgesics. The authors report that two weeks after treatment, no additional adverse events occurred. The study was

POEMs (patient-oriented evidence that matters) are provided by EssentialEvidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, please see http://www.essentialevidenceplus.com. Copyright Wiley-Blackwell. Used with permission.

For definitions of levels of evidence used in POEMs, see http://www.essentialevidenceplus.com/product/ebm_loe.cfm?show=oxford.

To subscribe to a free podcast of these and other POEMs that appear in AFP, search in iTunes for “POEM of the Week” or go to http://goo.gl/3niWXb.

This series is coordinated by Sumi Sexton, MD, Associate Deputy Editor.

A collection of POEMs published in AFP is available at http://www.aafp.org/afp/poems.

 

 

Want to use this article elsewhere? Get Permissions

CME Quiz

More in AFP


Editor's Collections


Related Content


More in Pubmed

MOST RECENT ISSUE


Oct 15, 2017

Access the latest issue of American Family Physician

Read the Issue


Email Alerts

Don't miss a single issue. Sign up for the free AFP email table of contents.

Sign Up Now

Navigate this Article