Gastrointestinal agents Md Yousuf Ansari

Gastrointestinal agents Acidifiers: Ammonium chloride* and Dil. HCl nonliving Gastrointestinal agents Acidifiers: Ammonium chloride* and Dil. HCl Antacid: Ideal properties of antacids, combinations of antacids, Sodium Bicarbonate*, Aluminum hydroxide gel, Magnesium hydroxide mixture Cathartics: Magnesium sulphate, Sodium orthophosphate, Kaolin and Bentonite Antimicrobials: Mechanism, classification, Potassium permanganate, Boric acid, Hydrogen peroxide*, Chlorinated lime*, Iodine and its preparations Disinfectants Living Kill Antiseptic Germicides Bacteriostatic An antacid is a substance which neutralizes stomach acidity, used to relieve heartburn, indigestion or an upset stomach Acidifiers are inorganic chemicals that either produce or become acid Antimicrobial agents are the chemicals and their preparation in reducing or preventing infection due to microorganisms In medicine, a cathartic is a substance that accelerates defecation

Acidifiers are inorganic chemicals that either produce or become acid Gastric acidifiers, used in controlling pH in stomach. Urinary acidifiers, used in controlling pH in urine. Systemic acidifiers, used in controlling pH in all the parts of body.

Antacids: Mechanism of Action Promote gastric mucosal defense mechanisms Secretion of: Mucus: protective barrier against HCl Bicarbonate: helps buffer acidic properties of HCl Prostaglandins: prevent activation of proton pump which results in  HCl production

Antacids: Mechanism of Action (cont'd) Antacids DO NOT prevent the over-production of acid Antacids DO neutralize the acid once it’s in the stomach They have a quick onset of relief but last for a short duration. They have a quick onset of relief but last for a short duration.

Antacids: Drug Effects Reduction of pain associated with acid-related disorders Raising gastric pH from 1.3 to 1.6 neutralizes 50% of the gastric acid Reducing acidity that reduces pain

Antacids (cont'd) Used as alone or in combination with other antacids that may reduced constipation.

Antacids: Aluminum Salts Forms: carbonate, hydroxide Have constipating effects Often used with magnesium to counteract constipation Examples Aluminum carbonate: Basaljel Hydroxide salt: AlternaGEL Combination products (aluminum and magnesium): Gaviscon, Maalox, Mylanta, Di-Gel

Antacids: Magnesium Salts Forms: carbonate, hydroxide, oxide, trisilicate Commonly cause diarrhea; usually used with other antacid agents to counteract of this undesirable effect It is dangerous, when used with renal failure or disease —the failing kidney cannot excrete extra magnesium, resulting in hypermagnesemia

Antacids: Magnesium Salts (cont'd) Examples Hydroxide salt: magnesium hydroxide Mg(OH)2 Carbonate salt: Gaviscon (also a combination product) Combination products such as Maalox, Mylanta (aluminum and magnesium)

Antacids: Calcium Salts There are different forms to be prepared but the most common is carbonate of calcium. They may cause constipation after taking. They may cause kidney stones. Long duration of acid action may cause increased gastric acid secretion (hyperacidity rebound) Often advertised as an extra source of dietary calcium Example: Tums (calcium carbonate)

Antacids: Sodium Bicarbonate It is highly soluble in nature Buffers have acidic properties to counter HCl Quick onset, but short duration May cause metabolic alkalosis Sodium content may cause problems in patients with hypertension, or renal insufficiency (fluid retention)

Antacids and Antiflatulents Antiflatulents: used to relieve the painful symptoms associated with gas Several agents are used to bind or alter intestinal gas and are often added to antacid combination products

Antacids and Antiflatulents (cont'd) OTC antiflatulents Activated charcoal Simethicone Alters elasticity of mucus-coated bubbles, causing them to break Used often, but there are limited data to support effectiveness