ANTI-ULCER DRUGS

• Slide presentation by-

ANURAG CHANDA B.PHARM , 5th SEMESTER

GURUNANAK INSTITUTE OF PHARMACEUTICAL SCIENCE AND TECHNOLOGY

What is Peptic Ulcer?• Peptic /stomach

ulcer is the condition in which imbalance of aggressive factor and defensive factors.

• Aggressive factor : Gastric acid, gastrin, pepsin

• Defensive factor : Prostaglandin, mucosa, bicarbonate

•Abdominal pain, classically epigastric with severity relating to mealtimes, after around 3 hours of taking a meal.•Loss of appetite and weight loss.

•Waterbrash (rush of saliva after an episode of regurgitation to dilute the acid in esophagus)

•Nausea, and copious vomiting

Classification Of Antiulcer Agent

1) Reduction of gastric acid secretion

H2 antihistamines: Cimetidine, ranitidine, famotidine

PPI’s : Omeprazole, lansoprazole, pantoprazole

Anticholinergics: Pirenzepine

Prostaglandin analogues:- Misoprostol

2) Neutralization of gastric acid by antacids-

Systemic : Sodium bicarbonate, sod. Citrate

Nonsystemic : Mg hydroxide, Mg trisilicate, Al hydroxide gel,

calcium carbonate

3) Ulcer protectives: Sucralfate, CBS ( Colloidal Bismuth Subcitrate)

4) Anti-H. pyloric drugs: Amoxicillin, clarithromycin, metronidazole,

tinidazole, tetracycline

Ranitidine- a nonimidazole H2, has several desirable features

as compared to cimetidine. 5 times more potent than cimetidine no androgenic action, does not increase prolactin secretion Lesser permeability into brain Overall evidence of side effects is lower: headache,

diarrhoea/constipation, dizziness have an incidence similar to placebo.

Famotidine – a thiazole ring containing H2 blocker which binds tightly to H2 and exhibits longer duration of action despite elimination t1/2 of 2.5-3 hours.

Oral bio-availability of famotidine is 40-50% and is excreted by kidney, 70% in the unchanged form Incidece of adverse effects is low: headache, dizziness, bowel upset rarely disorientation and rash have been reported Because of higher potency it is considered more suitable for ZE syndrome and for preparation pneumonia.

Antacid :- These are the basic substances which neutralize gastric acidity.. Systemic antacid : Sodium bicarbonate, water soluble, acts i.v. duration of action is short. Potent neutralizer, pH may rises above 7. Produces CO2 in stomach which leads to distention, discomfort. Non-systemic antacid: These are insoluble and poorly absorbed basic compound. React in stomach with acid to form respective chloride salts. Aluminium hydroxide gel: The Al+³ ions relaxes smooth muscle leads to delay in gastric emptying. This causes constipation.

Proton pump inhibitors-OMEPRAZOLE- Most active drug of this groupPowerful inhibitor of gastric acid secretion, when

sufficient dosage of about 20mg per day given the acid production can be diminished by more than 95%

It is bio-available upto 50%.

Ulcer Protective's – Sucralfate:

It a basic aluminium salt of sulphated sucrose, a drug of its own kind.

It has no acid neutralising action, but delay’s gastric emptying, it’s own stay in stomach is prolonged.

It is minimally absorbed after oral administration, action is entirely local

It promotes healing of both duodenal and peptic ulcer, efficacy has been found similar to cimetidine at four weeks.

It is considered to be superior in patients who continue to smoke.

These are infrequently used now of need for large well timed daily doses and the availability of simpler H2 blockers/PPI.

Anti Helicobacter pylori drugs H pylori: Spiral- shaped, pH-sensitive,

gram-negative bacteria. It attaches to the surface epithelium

beneath the mucus, has high urease activity

Produces ammonia which maintains a neutral microenvironment around the bacteria. Promotes back diffusion of H+

Antimicrobials found clinically effective against H.pylori : Amoxicillin, clarithromycin, metronidazole.

Single drugs rapidly develops resistance (metronidazole).

CBS is active against H.pylori and resistance does not develop to it.

ProglumideACh

PGE2

Histamine Gastrin

Adenyl cyclase

_+

ATP cAMP

Protein Kinase (Activated)

Ca++

+

Ca++

Proton pump

K+ H+

Gastric acid

Parietal cell

Lumen of stomach

AntacidOmeprazole

Ranitidine

M3

Misoprostol

_

__

_

+

PGE receptor

+

+

Gastrin recept

or+

+

+

THANK

YOU

Reference-1)Essentials of pharmacology byK.D. Tripathi2)Introduction to pharmacology by S.K kulkarni3) Foye’s principles of medicinal chemistry

by thomas m. lemke 4)Wikipedia.com5)Google.com