Antacids

1. Course Instructor: Dr . Rajib Bhattacharjee Presentation on “Drugs act on git ” Antacids

2. Prepared By: Md. Mohabbulla Mohib Istiaque Hasan Faisal Bin Kamal AKM Faisal

3. Physiology of “GIT”

4. Physiology of Gastrointestinal System

5. Gastrointestinal Tract Upper GIT consists of structures that aid in the ingestion and digestion of food includes the mouth, esophagus, stomach, duodenum Ingestion is the process of consuming something and taking it into the body. Digestion is the mechanical and chemical breaking down of food into smaller components, to a form that can be absorbed Lower GIT consists of the small and large intestines

6. Gastrointestinal Tract Mouth Salivation Mastication Major Structures in the Mouth teeth – to grind the food salivary glands – moisten food and mucous membranes and begin carbohydrate digestion tongue – to push the food to the pharynx to initiate swallowing Esophagus the lower esophageal sphincter (LES) prevents reflux of food in the stomach back into the lower esophagus

7. Gastrointestinal Tract Stomach made up of 5 layers of smooth muscle The mucus lining of the stomach protects the stomach walls from the action of stomach acid The walls of the stomach are lined with parietal cells that secrete mucus, pepsinogen and hydrochloric acid. 2 types of contractions: 1.) tonus contractions – continuous contractions 2.) rhythmic contractions – may be slow or fast – responsible for the mixing of food and peristaltic movement

8. Stomach

9. Heartburn

10. What is heartburn? When excess acid is produced a condition known as acid indigestion results. If excess acid is forced into the esophagus acid reflux or “heart burn” results. These conditions are sometimes called gastro-esophageal reflux disease (GERD).

11. Causes of Acid Indigestion Excess stomach acid results in a state of discomfort known as acid indigestion Acid indigestion may result form a variety of factors including: Overeating Alcohol consumption Eating certain foods Anxiety Smoking Certain Drugs, i.e. Aspirin

12. Pathophysiology of Heartburn If the Lower Esophageal Sphincter (LES) is not working properly creating a dysfunction – the acid from the stomach can backflow into the esophagus.

13. Antacids

14. What is Antacids? Antacids are a form of medicine used (normally in a tablet or liquid form) to help restore the pH balance in your stomach. It is an OTC drug. It is mainly weak bases that are used to neutralize excess stomach acid Most antacids are weak inorganic bases Common examples include CaCO 3 NaHCO 3 Al(OH) 3 Mg(OH) 2 Alginate Antacids

15. Ideal Characteristics of Antacids should not absorbable or cause systemic alkalosis. should not liberate carbon dioxide &cause rebound hyperacidity. should not interfere with absorption of food. should not be a laxative or cause constipation. should be quick acting & exert its effect over a longer period of time . should buffer in the pH range 4-6. should probably inhibit pepsin . should be inexpensive.

16. Mechanism of Action of Antacids

17. Mechanism of Action of Antacids Antacids directly neutralize acidity, increasing the pH In addition to neutralizing excess stomach acid they may be helpful in relieving pain and discomfort, and allowing the mucus layer in the stomach lining to heal . They are often used to treat ulcers by preventing the stomach acids from attacking the stomach lining allowing it to heal . Although their principle mechanism of action is reduction of intra gastric acidity, they can also promote mucosal defense mechanism by mucosal prostaglandin products.

18. Mechanism of Action of Antacids Reduction of pain associated with acid-related disorders Raising gastric pH from 1.3 to 1.6 neutralizes 50% of the gastric acid. Raising gastric pH 1 point (1.3 to 2.3) neutralizes 90% of the gastric acid.

19. How different Types of Antacids work CALCIUM CARBONATE Calcium Carbonate is a strong and fast-acting antacid. Antacids that contain calcium carbonate may work longer than those containing sodium bicarbonate or magnesium. CaCO 3 + 2 HCl  CaCl 2 + H 2 O + CO 2

20. ALUMINUM AND MAGNESIUM Aluminum salts dissolve slowly in the stomach, gradually relieving heartburn symptoms. But they may cause constipation. Magnesium salts on the other hand, act quickly to neutralize acid but are known to cause diarrhea. Because the effects of aluminum and magnesium can balance each other out, using them together is often considered an effective treatment for digestive upset. Al(OH) 3 + 3 HCl  AlCl 3 + 3 H 2 O Mg(OH) 2 + 2 HCl  MgCl 2 + 2 H 2 O

21. SODIUM BICARBONATE Sodium bicarbonate can work quickly to relieve heartburn symptoms. But it's also quickly eliminated from the stomach so relief may not last long. NaHCO 3 + HCl  NaCl + H 2 O + CO 2

22. Alginate Antacids Alginate antacids don't work the way other antacids do. These antacids contain both calcium carbonate and alginic acid. The alginic acid helps form a barrier that floats on top of the acid in your stomach. This barrier helps prevent stomach acid from moving up into esophagus . The calcium carbonate works to neutralize the stomach acid that pushes through the barrier and into your esophagus.

23. Side Effects

24. Side Effects of Antacids

25. Who cannot take antacids Patient with kidney failure or heart disease : Sodium bicarbonate has high sodium content and is not appropriate for people who are on salt restricted diets or have congestive heart failure, high blood pressure, or kidney problems. In pregnancy : If you are pregnant, antacids are safe to use for heartburn symptoms. But do not use antacids that have sodium bicarbonate. They can cause fluid buildup. During pregnancy it is okay to use antacids that have calcium carbonate (such as Tums). Problem with liver and kidney : If you have a problem with the function of your kidneys or liver, you should be careful with using antacids. All drugs are broken down and removed from the body by the combined action of the liver and kidneys. If your kidneys are not working correctly, it is possible that too much of the drug will build up in your body.

26. Drug-Drug interactions When antacids are taken with acidic drugs such as digoxin , phenytoin , chlorpromazine , isoniazid, they cause the absorption of the acidic drugs to be decreased, which causes low blood concentrations of the drugs, which ultimately results in reduced effects of the drugs. Antacids that contain magnesium hydroxide when taken with some other medications (such as tetracycline) will bind to the drug, and reduce its absorption and effects

27. Adverse Effect Constipation can occur in patients using calcium carbonate and aluminum containing antacids. Diarrhea is a common adverse effect of magnesium- and sodium-containing antacids. If diarrhea occurs, the patient may alternate the antacid mixture with aluminum hydroxide.

28. REFERENCES The pharmaceutical basis of therapeutics,12 edition; Goodman & Gilman. http:// www.heartburn.com/a-to-z-guides/nonprescription-medications-and-products-antacids-and-acid-reducers http://bodyecology.com/articles/low_stomach_acid_symptoms.php#.UisH6m3-tyM http://www.patient.co.uk/health/antacids http://www.drugbank.ca/drugs/DB01390 https://www.inkling.com/read/pharm-phys-anesthetic-practice-stoelting-4th/chapter-26/antacids http:// pharmacy.utah.edu/pharmtox/common_meds/icm15.htm http:// www.drugbank.ca/drugs/DB06723

29. Thank you