antacids antacids neutralize gastric acid and reduce gastric irritation and relieve the symptoms of heartburn they enhance mucosal protection but do not coat any existing ulcers antacids are used for peptic ulcer disease and gird antacids should be taken 1 to 3 hours after meals and at bedtime and when symptomatic because antacids are short acting and are only effective when there is acid to neutralize antacids should be taken 1 hours apart from other medications to prevent interference antacids usually come in chewable tablets or liquid form chewable tablets should be chewed thoroughly so the protective foam can be formed in the mouth before swallowing followed with a glass of water or milk liquid forms should be shaken before taking there are several active ingredients used in ant acids for example aluminum hydroxide magnesium hydroxide and calcium carbonate they all neutralize gastric acid and have their own side effects aluminum hydroxide reduces phosphate absorption and leads to hypo phosphate Maya it also contains high amounts of sodium so use with caution in patients with hypertension and heart failure constipation is a common side effect calcium carbonate or commonly known as Tums can also cause constipation belching and flatulence magnesium hydroxide on the other hand is a laxative and can cause diarrhea it is contraindicated in testinal obstruction renal impairment because magnesium can accumulate an example is milk of magnesia