Last reviewed 2026-04-22 · How we verify

Maalox plus Benadryl

This combination antacid and antihistamine reduces stomach acid while blocking histamine-mediated gastric secretion and providing anticholinergic effects.

This combination antacid and antihistamine reduces stomach acid while blocking histamine-mediated gastric secretion and providing anticholinergic effects. Used for Heartburn and acid indigestion, Peptic ulcer disease.

At a glance

Mechanism of action

Maalox (aluminum hydroxide and magnesium hydroxide) neutralizes gastric acid through direct chemical reaction, while Benadryl (diphenhydramine) is an H1 receptor antagonist that reduces histamine-mediated acid secretion and provides anticholinergic effects to decrease gastric motility. This combination approach addresses both existing acid and the mechanisms driving acid production.

Approved indications

• Heartburn and acid indigestion
• Peptic ulcer disease

Common side effects

• Constipation
• Diarrhea
• Drowsiness
• Dry mouth

Key clinical trials

• Effects of Photobiomodulation (PBM) on Pain After Presentation of Aphthous Ulcers in Pediatric Dental Patients (PHASE4)
• Gelclair at Conditioning or After Oral Mucositis Diagnosed vs. Magic Mouth Wash in Stem Cell Transplant Recipients (PHASE4)
• Study to See How Safe Curcumin is and How Well it Works When Used to Treat Mucositis in Patients Getting Chemotherapy (PHASE1, PHASE2)
• Effect of Over-the-counter Toothpastes on Chemotherapy-induced Oral Mucositis (PHASE2)
• Morphine Mouthwash for Management of Oral Mucositis in Patients With Head and Neck Cancer (PHASE2, PHASE3)

Primary sources

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