1. Gastrointestinal Agents ( GIA)

2. Inorganic agents used to treat GIT
Inorganic agents used to treat gastrointestinal disorders include:
Products for altering gastric pH
-Acidifying Agents: Used to treat achlorhydria (absence of HCl in the gastric secretion)
e.g.- Diluted HCl
-Antacids: Used to treat hyperchlorhydria and peptic ulcer.
2) Protectives for intestinal inflammation
3) Adsorbents for intestinal toxins
4) Cathartics or laxatives for constipation

3. Acidifying Agents
Achlorhydria is the absence of HCl in the gastric secretion. Lt is common in otherwise normal individual after age 50 years.
Gastric HCl functions by killing the bacteria in ingested food& drink, softening fibrous food, promoting formation of the proteolytic enzyme, pepsin.

4. The symptoms of achlorhydria
1-mild diarrhea( frequent bowel movement)
2-epigastreic pain ( upper abdominal pain ).
3- sensitive to food ( spicy ).

5. Treatment of Achlorhydria
Dilute HCl solution ( 200ml ) prepared .
Dose 15ml for each .
The use of dil HCl because to avoid exposure of dental enamel

6. Antacids
Agents are given or administered to neutralize excess HCl which may be causing pain & possible ulceration.

7. When anatcids are described?
1- uncomfortable feeling from over eating
2-heartburn
3-A growing hungry feeling between meals.

8. Treatment of hyperacidity
1- Anticholinergic agents.
2- Inorganic antacids ( Aluminum hydroxide and Magnesium hydroxide ).
3-In case of ulceration, H2 –antagonist
Cimetidine, Ranitidine, …
4-Bed rest
5- Surgical if necessary ( Bleeding ).

9. Hyperacidity developed , the result can range from gastritis ( inflammation of gastric mucosal to peptic ulcer.A peptic ulcer can be located in the lower end of the esophagus.
Also, stomach ulcer( gastric ulcer), duodenum ulcer.

10. Patients suffering from burn, which is due to gastric acid entering the esophagus either a blechor upon lying in bed ( Reflux ).
Frequently, these people obtained relief by sleeping in a bed elevated at the head to reduce the flow of gastric fluid from the stomach into esophagau.

11. Types of peptic ulcers There are TWO types. 1- chronic ulcer.
2- acute ulcer.
Chronic ulcer rather than acute ,
Complications will include hemorrhage , may be leads to other disease ( CA).

12. Treatment of Ulcer
Range from diet
Antacids
Anticholinergic agents.

14. Antacids Therapy
Antacids are alkaline bases used to neutralized the excess gasrtic HCl associated with gastric & peptic ulcers.

15. Antacids Products( drugs)
* Sodium bicarbonate Na2HCO3
**Aluminum antacid products
*** Magnesium antacid products.
Combination therapy( Al + Mg) products.
Maloox .
There is no ideal antacids

16. Selection of pharmaceutical Anatcids
The antacid should not be absorbable or cause systemic alkalosis.
 It should not be laxative or cause constipation
 It should buffer in the pH 4-6 range
 It should be rapidly effective and maintain its effect over a long period of time.
 It should probably inhibit pepsin but should not completely inactivate peptic digestion.
 It should not produce rebound acidity or excessive eructation (belching).
 It should not cause large evolution of gas by reacting with gastric HCl.
 It should not affect the absorption of food, nutrient and vitamin.
 It should be non-irritant to stomach, intestine and should not cause diarrhea.
 It should be non-toxic, and palatable.
 It should be cheap and available.

17. Criteria for antacid products
In order for a product to be labeled an antacid according to FDA Antacid Panel it must consist of one or more approved (active) ingredients.
Each active ingredient must contribute at least 25% of the total acid-neutralizing capacity of the product.
 The finished product must contain at least 5mEq/dose unit of acid-neutralizing capacity and raise the pH of gastric secretions to 3.5 or greater within 15 minutes.
 No more than four active antacid ingredients can be combined in any one product

18. Classification of Antacids
Antacids are commonly classified in two groups:
Systemic Antacids & Nonsystemic antacids
Systemic Antacids:
Antacids(water soluble) which are absorbed in the systemic circulation (usually from the gut) and may cause metabolic alkalosis are called systemic antacids.
Common systemic antacids are: Sodium Bicarbonate, Sodium citrate, Sodium acetate, and Potassium citrate

19. On systemic Antacids:
Antacids which are not absorbed from the gut and does not interrupt acid base balance (metabolic alkalosis) are called nonsystemic antacids.
Non systemic antacids are divided into-Buffer antacid & Non-buffer antacid.
Buffer antacid:They limit the rise in pH of the gastric contents to below neutrality.
e.g. Aluminum Hydroxide Gel [Al(OH)3], Magnesium hydroxide [Mg(OH)2], Magnesium Trisilicate [2MgO.3SiO2.xH2O]
Non-buffer antacid:They potentially permit the elevation in pH even above neutrality.
e.g. Calcium carbonate [CaCO3], Calcium phosphate [Ca3(PO4)2], Magnesium oxide [MgO], Magnesium Carbonate [MgCO3]

20. Sodium bicarbonate NaHCO3
Sodium bicarbonate USP ( Baking Soda )
Used as antacids it can cause sharp increase in gastric pH up to 7
HCl + NaHCO NaCl + H2O + CO2
It is readily absorbed and sodium retention can result with continued use.

21. Sodium bicarbonate USP
Usual Dose ; 300mg- 2g four times daily
May be found in many combination therapy

22. Side effects of Sodium bicarbonate
1- it is readily absorbed.
2- it will inhibit the absorption of tetracyclines.
3- increase blood pressure.
4- Bad taste and form gases.

23. .To overcome this problem
Combination therapy between the sodium bicarbonate + Citric acid
May form effervescent

24. Aluminum containing antacids
Widely used, they are nonsystemic &
pH =3- 5
Because of libration of astringent aluminum cations Al +++, they ten to be constipation
Most cause increased fecal phosphate excreation due to formation of insoluble Aluminum phosphate in the intestine tract.

25. Types of Aluminium products
There are TWO types
1- Aluminum hydroxide gel ( suspension)
2- Aluminum hydroxide gel Tablets
Both gel and dry aluminum are popular antacids ( Famous)
Dose 5ml to 30 ml for suspension
1 to 4 chewable tablets.

26. The onset of action of the latter (Dried gel
The onset of action of the latter (Dried gel..)is slower, deepening on patient must first chew the tablet or simply suck on the tablet.
The degree of chewing will determine how finely divided will be the particles.

27. A problem with the gels is that of a loss of antacids properties on aging .This is more of a problem with dried gel than with the liquid suspension and seems to be related to the manufacturing process.
The rate of loss of antacids action is de-pendent upon pH used to ppt the gel.

28. The Al hydroxide gels are nonabsorbable and exert little.
If the gel is formed by ppt in a carbonate,/bicarbonate system, they may be some evolution in of CO2 ,due to reaction between HCl and HCO3-

29. Al hydroxide gel may be adsorb pepsin and interfere with adsorption with other drugs.
May be cause constipation , nausea, vomiting,.
For long period may be cause phosphate deficiency.

30. Calcium containing Antacids
Those used in medicine as CaCO3 are poorly absorbed salts which will only go into solution
CaCO Ca +2 +CO H2CO3
H2O CO2

31. Disadvantages Make gases Constipation
Contraindicated in patients with renal disease. gastric hemorrhage , hypertension, dehydration of electrolytes.

32. Magnesium containing Antacids
There are a large number of official magnesium antacids . They are porrly soluble salts & rate of dissolution is slow.
The problem is Magnesium carbonate
(MgCO3)4. Mg(OH)2.5H2O are laxatives
Dose ; 500 mg four times daily.

33. Magnesium Hydroxide Mg(OH)2
It is white powder, insoluble iun water,alcohol,only dissolve in dil acids
Mg(OH)2 = Mg OH H2O
At high doses, magnesiumhydtoxide used as Laxative.
When used as antacid usually found as combination therapy with Al.
Dose mg

34. Combination Therapy
Because no single antacids meets all the criteria for an ideal antacids, several combination therapy products of antacids
1-Aluminum hydroxide gel+ Magnesium hydroxide ( Aludrox) ( Maalox )
Found as Tablet or suspension ( Not laxative and not constipation)

35. Maalox Tablet or Suspension

36. Gaviscon Alginic acid + Sodium bicarbonate mixture
Attempt to provide relife of reflux esiphagus .
The bulk tablet is chewed.
Alginic acid is hydrophilic colloidal carbohydrate obtained from sea weed.
It make foam which floate on the top pf stomach.

37. Chewable Tablet

38. Protective's & Adsorbents
Agent are used for treat mild diarrhea
Diarrhea is a symptom and not a disease
Diarrhea may be acute or chronic
Acute diarrhea can be caused by bacteria , toxin, chemical poisons, drugs, allergy, disease

39. Damage or irritation to that of causing electrolytes to flow from body fluids into intestinal tract.( Short Time )
Electrolytes should be given to the patients.

40. Diarrhea is a serious condition, particularly for very young or elderly patients.
The loss of fluids & electrolytes can quickly lead to dehydration and electrolyte imbalances.
It is believed that some of the bacterial toxins stimulate the flow of electrolytes into the intestine.

41. Thereby increasing the intestinal osmoticload.

42. Chronic diarrhea
Can result from gastrointestinal surgery, carcinoma, chronic inflammation.
The chronic diarrhea for long time
The loss of electrolytes and fluids can quickly lead to dehydration and electrolytes imbalance.

43. Drugs used for treatment
1- Adsorbent
2-Antispasodic agent (organic agent )
3-Antibacterial ( Tetracycline)

44. 1- Adsorbents
Protective agents supposed to adsorb toxins, bacteria & viruses.
Bismuthsalts. [Bi(OH)2NO3]]4.BiO(OH).
Clays
Activated charcoal

45. Bismuth products Milk of Bismuth ( Bismuth cream )
A suspension contains bismuth hydroxide and bismuth subcarbonate .
Are water insoluble, may act as mild astringent and antiseptic action.

46. Bismuth subcarbonate It is USP, the chemical formula is:
[(BiO)2CO3]2 .H2O
Insoluble in H2O,but soluble in acids.
It is protective agent.

47. clays Kaolin is a native hydrate aluminum silicate
It is found in earth as clay, some times added to pectin used for children

48. It occurs as a soft,white or fait tyellow, when mix with H2O assumes a darker color and clay odor.
It is insoluble with H2O .It is usually found together with the vegetable bcarbohydrate pectin .
It is used as adsorbent.
It is interfer with Lincomycin

49. Activated Charcoal USP
Used as adsorbent in the treatment diarrhea
Now the drug of choice for poisoning as antidote.
Activated charcoal is recommended as a component of first aid kits.
Also, may be used as filter in gas mask.
It adsorb CO2,N2O, O2, N2, Amines,NH3,

50. Activated Charcoal is used in filters of gas masks because of its ability to adsorb gases.