Key Results

There were 89 participants enrolled in the trial who could be analyzed. Thirty received the viscous treatment, 31 the solution, and 28 antacid monotherapy. The mean age was early 40s, around two-thirds were female, and 80 percent were discharged with a gastrointestinal diagnosis.

All three treatments worked, and there was no statistical difference between groups. The solution group and antacid monotherapy group provided clinically important (>13 mm) analgesia at 30 minutes (17 mm and 20 mm, respectively), while the viscous group did not (9 mm). However, there was no statistically significant difference between the three treatments groups.

All three groups experienced additional pain relief by 60 minutes. The change in median pain scores was clinically significant (>13 mm) for all three arms (21 mm, 26 mm, and 32 mm).

Participants found antacid monotherapy to be the most palatable solution. The most frequent adverse effect was oral numbness. It was only reported in the lidocaine solution (26 percent) and viscous group (20 percent), not in the antacid monotherapy group.

Evidence-Based Medicine Commentary

1. Inclusion Criteria: Patients were enrolled prospectively based on their clinician providing an antacid therapy. This resulted in the inclusion of some patients with non-GI causes of pain. This could have decreased the effect size observed in the three different treatment groups.
2. Selection Bias: Patients were also not enrolled overnight. Patients who present on the night shift might be different than those who present during the day shift (for example, there might be different rates of alcohol-related gastritis, or patients might present with dyspepsia more often after larger evening meals, etc.). It is unclear if this issue would have affected the results and, if so, in what direction.
3. Blinding: The solutions were not made to look identical. This could have unblinded the trial to the nursing staff. The patients may also have been unblinded. Lidocaine has a bitter taste and causes oral numbness. This could have introduced a placebo effect into the trial. It is been shown that bitter-tasting treatments can increase the placebo effect.^6,7 However, given the direction of this bias toward the lidocaine-containing combination therapies, this would only strengthen our confidence in the results of no statistical difference with monotherapy alone.
4. Diagnosis: As stated, patients were enrolled if antacid therapy was provided regardless of the diagnosis. Some patients were found to have non-GI reasons for their epigastric pain. However, there are also multiple GI causes of pain (eg, dyspepsia, GERD, gastritis, peptic ulcer disease, etc.). This trial did not have a large enough sample size to determine if antacid plus lidocaine would be more effective than antacid monotherapy in any of these subgroups.
5. Other Comparisons: There was no comparison to any other medications such as H2 receptor antagonists, proton pump inhibitors, and anticholinergics. We do not know from this trial whether antacid alone or in combination with lidocaine would be better, worse, or similar to these other treatment modalities, nor whether the typical GI cocktail might fare better in combination with these other treatments.

Bottom Line

Consider using antacid monotherapy for patients presenting to the emergency department with epigastric pain rather than a lidocaine-containing combination therapy.