The difference between magnesium aluminum carbonate and famotidine lies in different efficacy, different contraindications and different adverse reactions. 1. Different efficacy: magnesium aluminum carbonate belongs to the gastric mucous membrane protective agent, can play a protective effect of gastric mucous membrane. Famotidine belongs to acid inhibiting drugs, its role is to inhibit gastric acid secretion. 2. Contraindications are different: Magnesium aluminum carbonate contraindications include allergy, hypomagnesemia. Contraindications of Famotidine include severe renal insufficiency, pregnant and lactating women. 3. Adverse reactions are different: magnesium aluminum carbonate adverse reactions are few and mild, a very small number of patients may have dyspepsia, vomiting and other adverse reactions. Famotidine can cause increased blood pressure, facial flushing, abdominal distension, constipation, thirst, headache, allergies and other adverse reactions. It is recommended to take Magnesium Aluminum Carbonate with Famotidine under the supervision of a physician and not on your own.