Date: September 22nd, 2020

Guest Skeptic: Dr. Chris Bond is an emergency medicine physician in Calgary. He is also an avid FOAM supporter/producer through various online outlets including TheSGEM.

Reference: Warren et al. Antacid monotherapy is more effective in relieving epigastric pain than in combination with lidocaine. A randomized double-blind clinical trial. AEM Sept 2020.

Case: A 34-year-old male presents to the emergency department with burning epigastric pain after eating two hours ago. He says he gets this from time to time but this is the worst it has ever been. He denies chest pain, shortness of breath, fever and vomiting. His vital signs are within normal limits and his abdominal exam reveals mild epigastric and left upper quadrant tenderness with no peritonitis.

Pink Lady Cocktail

Background: Patients presenting to emergency departments (EDs) with epigastric pain are typically treated with an antacid, either alone or combined with other medications. Such medications include viscous lidocaine, an antihistamine, a proton pump inhibitor, or an anticholinergic (1,2). In Canada we often use an antacid plus viscous lidocaine referred to as a “Pink Lady”. This is different than the alcoholic cocktail called a Pink Lady. In the US, combination treatment is often called a “GI Cocktail”.

There are mixed results from studies with varying methodological quality looking at acute dyspepsia management in the ED. One single-blind study comparing 30 mL of antacid with or without 15 mL of viscous lidocaine found the addition of lidocaine significantly increased pain relief, decreasing patient pain score by 40 mm compared to 9 mm with antacid monotherapy (3). Another single-blind RCT comparing antacid plus either benzocaine solution or viscous lidocaine found no statistical difference between the two interventions, however, there was no antacid monotherapy group (4).

A larger, double-blind RCT of 113 patients compared 30 mL of antacid monotherapy, antacid with 10 mL of an anticholinergic, and antacid with anticholinergic and 10 mL of 2% viscous lidocaine. This study found all treatments had clinical efficacy and there was no statistical difference in pain relief between the three treatment groups. The conclusion from Berman et al was to recommend antacid monotherapy (5).

Clinical Question: Is antacid monotherapy more effective in relieving epigastric pain than in combination with lidocaine?

ReferenceWarren et al. Antacid monotherapy is more effective in relieving epigastric pain than in combination with lidocaine. A randomized double-blind clinical trial. AEM Sept 2020.

  • Population: Adult patients with epigastric pain or dyspepsia presenting to the emergency department.
    • Excluded: Patients unable to consent or under 18 years of age.
  • Intervention: 
    • Arm 1 (Viscous): Received 10 mL oral lidocaine 2% viscous gel plus 10 mL antacid (traditional antacid/lidocaine mixture)
  • Comparison:
    • Arm 2 (Solution): Received 10 mL lidocaine 2% solution plus 10 mL antacid
    • Arm 3 (Antacid): Received 20 mL antacid alone
  • Outcome:
    • Primary Outcome: Change in pain scores on 100mm visual analog scale (VAS) at 30 minutes after treatment.
    • Secondary Outcomes: Medication palatability (taste, bitterness, texture, and overall acceptability) using a VAS, change in pain score 60 minutes post administration and adverse events.

Dr. Jamie Warren

This is an SGEMHOP episode which means we have the lead author on the show, Dr. Jaimee Warren. She is a first-year doctor at the Royal Melbourne Hospital and an aspiring emergency and retrieval physician. She hopes to one day work in rural and extreme environments.

Authors’ Conclusions: “A 20 mL dose of antacid alone is no different in analgesic efficacy than a 20 mL mixture of antacid and lidocaine (viscous or solution). Antacid monotherapy was more palatable and acceptable to patients. A change in practice is therefore recommended to cease adding lidocaine to antacid for management of dyspepsia and epigastric pain in the ED.”

Quality Checklist for Randomized Clinical Trials:

  1. The study population included or focused on those in the emergency department. Yes
  2. The study participants were adequately randomized. Yes
  3. The randomization process was concealed. Yes
  4. The participants were analyzed in the groups to which they were randomized. Yes
  5. The study participants were recruited consecutively (i.e. no selection bias). No
  6. The participants in both groups were similar with respect to prognostic factors. Unsure
  7. All participants were unaware of group allocation. No
  8. All groups were treated equally except for the intervention. Yes
  9. Follow-up was complete (i.e. at least 80% for both groups). Yes
  10. All patient-important outcomes were considered. Yes
  11. The treatment effect was large enough and precise enough to be clinically significant. Yes

Key Results: The trial enrolled 94 patients and 89 could be analyzed (30 viscous, 31 solution and 28 antacid group). The mean age was in the early 40’s, with around 2/3 female and 80% of patients were discharged with a gastrointestinal diagnosis. 

All three treatments (viscous, solution or antacid monotherapy) worked and there was no statistical difference between groups.

  • Primary Outcome: The lidocaine solution with antacid and antacid monotherapy provided clinically important (>13 mm) analgesia at 30 minutes (17mm and 20mm), viscous lidocaine with antacid did not (9mm). However, this still did not result in a statistically significant difference between treatments.
  • Secondary Outcomes: At 60 minutes, all treatment groups (viscous, solution and antacid monotherapy) experienced additional pain relief. The change in median pain scores was clinically significant (>13 mm) for all three arms (21mm, 26mm, and 32mm).

The most frequent adverse effect was oral numbness (lidocaine viscous 20% and lidocaine solution 26%). Two patients in the viscous arm reported dizziness and tiredness (7%), and four patients in the solution arm reported cough, nausea, and dizziness (13%). One patient in the antacid arm reported a dry mouth (4%).

Participants found antacid monotherapy to be the most palatable solution, with statistically significant differences in taste, bitterness, and overall acceptability.

Listen to the podcast on iTunes to hear Jaimee’s responses to our ten nerdy questions.

1. Inclusion Criteria: Patients were enrolled prospectively based on the clinician providing an antacid therapy. This resulted in a large group of patients having non-GI causes of pain. Why not enroll patients for whom the final diagnosis was dyspepsia or epigastric pain after ED workup?

2. Selection Bias: Why were patients that presented overnight excluded from enrolment (funding for research staff 24/7)? Are these patients potentially different (eg. more severe presentations of alcohol related gastritis, large meals for dinner followed by lying down or other reasons)?

3. Unbalanced Groups: In Table 1, it appears that more patients in the lidocaine arms had prior proton pump inhibitor (PPI) use and more prior upper GI related diagnoses (eg. Peptic ulcer disease/gastritis/gastroesophageal reflux disease). It also appears the viscous group received more rescue analgesics in the ED. Can you confirm these are all non-statistically significant differences between groups as the p-values are not documented?

4. Blinding of Staff: The solutions were not made to look identical. This could have unblinded the trial to the nursing staff. Do you think that could have impacted the results and did you consider asking the nurses which group they felt the participant was randomized?

5. Placebo Effect: The patients may also have been unblinded and susceptible to a placebo effect. Lidocaine has a bitter taste and can cause oral numbness. It has been demonstrated that bitter tasting treatments can increase the placebo effect.

  • Wright et al. If it Tastes Bad it Must Be Good: Consumer Naïve Theories and the Marketing Placebo Effect. Intern. J. of Research in Marketing 2013
  • Kihlstrom. Placebo: Feeling Better, Getting Better, and the Problems of Mind and Body. Mcgill J Med. 2008
  • Evans FJ. The placebo response in pain reduction. In: Bonica JJ, editor. Advances in Neurology. New York: Raven; 1974

6. Diagnosis: Do you think that the effectiveness of antacid monotherapy is the same whether the diagnosis is dyspepsia vs. GERD vs. gastritis vs. PUD?

7. Primary Outcome: Your primary outcome was a change in 100mm VAS at 30 min. While that is an important patient-oriented outcome (POO) what about length of relief? Your secondary outcome was 60min. What about a longer time frame or return to ED within 24hrs?

8. Other Comparisons: Can you comment on how use of these medications compares with H2 receptor antagonists and PPIs in terms of efficacy for treating dyspepsia and epigastric pain in the ED?

9. Down Under: This was a single centre study conducted in Melbourne, Australia. Patient expectations can be different depending on the country. What are your thoughts to the external validity to other countries (UK, USA, Canada, Europe, etc)? Do you think you would find similar results?

10. Anything Else: Is there anything else you’d like to comment on about your paper that we have not asked, or you think is important for the SGEMers to know?

Comment on Authors’ Conclusion Compared to SGEM Conclusion: We generally agree with the authors’ conclusions but would say that a change in practice should be “considered” rather than “recommended”.

SGEM Bottom Line: Consider using antacid monotherapy in place of lidocaine/antacid combination therapy for patients with dyspepsia.

Case Resolution: You give your patient 20 mL of antacid and his epigastric pain improves. You suggest he try antacids in the future if he has recurrent post prandial pain and follow-up with his family physician.

Dr. Chris Bond

Clinical Application: Give antacid monotherapy for dyspepsia in the emergency department.

What Do I Tell the Patient: We have given you some medication to treat your stomach pain. This is usually related to eating and sometimes to reflux or in rare cases an ulcer. If you are having recurrent pain you can use over the counter antacid medications. If it is persistent and frequent, you may need to see your family doctor to start a daily medication and perhaps have more investigations.

Keener Kontest: There was no winner last week. Many people guessed Philipp Bozzini. However, the question was who was considered the “father of endoscopy”. According to wikipediaAntonin Jean Desormeaux was considered the father of endoscopy. This is because he made significant improvements to the early endoscope by Bozzini and was the first to successfully use it on a living patient.

Listen to the SGEM podcast to hear this weeks’ question. Send your answer to with “keener” in the subject line. The first correct answer will receive a cool skeptical prize.

SGEMHOP: Now it is your turn SGEMers. What do you think of this episode on Tweet your comments using #SGEMHOP.  What questions do you have for Jaimee and her team? Ask them on the SGEM blog. The best social media feedback will be published in AEM.

Also, don’t forget those of you who are subscribers to Academic Emergency Medicine can head over to the AEM home page to get CME credit for this podcast and article. We will put the process on the SGEM blog:

  • Go to the Wiley Health Learning website
  • Register and create a log in
  • Search for Academic Emergency Medicine – “September”
  • Complete the five questions and submit your answers
  • Please email Corey ( with any questions or difficulties.

Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine.


  1. Peter J Kahrilas, M. Medical management of gastroesophageal reflux disease in adults. 2018. Available from:
  2. Talley, N.J. and N. Vakil, Guidelines for the management of dyspepsia. Am J Gastroenterol, 2005. 100(10): p. 2324-37.
  3. Welling, L.R. and W.A. Watson, The emergency department treatment of dyspepsia with antacids and oral lidocaine. Ann Emerg Med, 1990. 19(7): p. 785-8.
  4. Vilke, G.M., et al., Prospective randomized study of viscous lidocaine versus benzocaine in a GI cocktail for dyspepsia. J Emerg Med, 2004. 27(1): p. 7-9.
  5. Berman, D.A., R.S. Porter, and M. Graber, The GI Cocktail is no more effective than plain liquid antacid: a randomized, double blind clinical trial. J Emerg Med, 2003. 25(3): p. 239-244.