1. Gastrointestinal agents
Md Yousuf Ansari

2. 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

3. 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.

4. 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

5. 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.

6. 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

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

8. 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

9. 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

10. 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)

11. 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)

12. 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)

13. 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

14. 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