Using N-acetylcysteine plus simethicone before upper endoscopy to improve mucosal visibility

Randomized Controlled Trial to Evaluate the Effect of Premedication With N-acetylcysteine and Simethicone on Mucosal Visibility During Elective Upper Gastrointestinal Endoscopy Using the TUGS Score

This trial will test whether taking N-acetylcysteine and simethicone by mouth shortly before an upper endoscopy helps doctors see the lining of the esophagus, stomach, and duodenum better in adults without active GI bleeding.

Quick facts

• Phase: PHASE2
• Study type: Interventional
• Enrollment: 132 (estimated)
• Ages: 18 Years to 99 Years
• Sex: All
• Sponsor: Hospital General de Mexicali (other)
• Locations: 2 sites (Mexicali, Estado de Baja California and 1 other locations)
• Trial ID: NCT07245095 on ClinicalTrials.gov

What this trial studies

This is a randomized, double-blind, placebo-controlled multicenter trial comparing a single oral dose of N-acetylcysteine (600 mg) plus simethicone (100 mg) versus placebo (water) given 20–60 minutes before elective diagnostic upper endoscopy. Trained endoscopists blinded to treatment allocation will score mucosal cleanliness using the Toronto Upper Gastrointestinal Cleanliness Score (TUGS). Secondary measures include recording significant endoscopic findings, histopathology results, and any adverse events to evaluate tolerability and safety. Variables such as age, sex, BMI, fasting time, site, and endoscope model will be recorded and controlled for in analysis.

Who should consider this trial

Good fit: Adults aged 18 to 70 scheduled for elective diagnostic upper endoscopy who are not actively bleeding and who have no known hypersensitivity to N-acetylcysteine or simethicone.

Not a fit: People with active gastrointestinal bleeding, prior gastric/bariatric surgery, known motility disorders, pregnant or breastfeeding individuals, or those allergic to the study drugs are excluded and unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this simple premedication could make the mucosa clearer during endoscopy, improving lesion detection and potentially reducing the need for repeat procedures.

How similar studies have performed: Previous trials using simethicone with or without mucolytic agents have generally shown improved mucosal visibility, so the combined NAC-plus-simethicone approach has supportive prior evidence though practices vary by center.

Eligibility criteria

Inclusion Criteria:

* Men and women aged 18 to 70 years old.
* Patients who agree to participate in the clinical trial.
* Patients without active gastrointestinal bleeding.
* Signing of informed consent form.

Exclusion Criteria:

* Patients with a history of hypersensitivity to N-acetylcysteine
* Patients with a history of hypersensitivity to simethicone
* Patients with a previous endoscopic diagnosis
* Patients with a history of gastric or bariatric surgery
* Patients with a history of motor disorders (e.g., scleroderma, diabetic gastroparesis)
* Patients taking medications that delay gastric emptying (GLP-1 analogues)
* Pregnant or breastfeeding patients
* Patients who do not agree to participate in the clinical trial

Where this trial is running

Mexicali, Estado de Baja California and 1 other locations

• Hospital Almater — Mexicali, Estado de Baja California, Mexico (RECRUITING)
• Hospital General de Mexicali — Mexicali, Estado de Baja California, Mexico (RECRUITING)

Study contacts

• Study coordinator: Luis Andre Sanchez Perez, Resident

Conditions: Esophagogastroduodenoscopy, Simethicone, N-Acetylcysteine, Premedication, Visualization, Esophagogastroduodensocopy Procedure, Placebo - Control, Gastritis Associated With Helicobacter Pylori