Peptic_Ulcer_Disease

1. PEPTIC ULCER DISEASE
PHARMACOLOGY
By Dr Safinaz I. Khalil

2. OBJECTIVES
• 1-Introduction include briefing of pathogenesis and diagnosis of Peptic Ulcer Disease
• 2-Erradication of H Pylori regimen
• 3-Mechanism of Action of Proton Pump Inhibitors, Drugs used ,Side effects
• 4-Mechnism of actions of Antiacids , drugs used and side effects
• 5- Mechanism of action of Mucosal Protective agents, drugs used ,side effects
• 6-Summary

3. The Pathogenesis of peptic ulcer disease is not fully
understood, although, several major causative factors are
recognized:
, Infection with gram-negative Helicobacter pylori,
(NSAID) use ,increased hydrochloric acid secretion, and
inadequate mucosal defense against gastric acid.

7. ERADICATION OF H PYLORI
REGIMEN
•Treating H Pylori infection is a challenge nowadays because of
many reasons .The single important one remain the antibiotic
resistance to the H pylori. Triple therapy with proton pump
inhibitors (PPI regimen) was the mainstay one for treating H
pylori but now this line has developed a resistance for many
reasons.

8. FIRST LINE TRIPLE
ERADICATION REGIMEN
• Consists of Proton Pump Inhibitor (PPI) with two antibiotics
given BID for 14 days
• Lansoprazole 30 mg po BID, Metronidazole 500 mg po BID,
Clarithromycin 250 mg po BID
• Common side effects of the triple regimen:
• Diarrhea, nausea
•

9. SECOND LINE TREATMENT IS
QUADRABLE THERAPY

10. EVIDENCE FOR NEWER THERAPIES
SEQUENTIAL THERAPY
•Due to the increased first line H pylori infection therapy
growing resistance to antibiotics used in this regimen .The
novel line treatment is sequential therapy which consists of
two steps:
•PPI with amoxicillin for the first 5 days followed by triple
therapy that includes a PPI, clarithromycin and tinidazole for
another 5 days and this is a 10-days program.

11. SALVAGE THERAPY
•Some patients fail to respond to the sequential
therapy, for these patients salvage therapy
consists of PPI, amoxicillin and
levofloxacillin administered for 10 days.

12. Regulation of gastric acid secretion
Gastric acid secretion by parietal cells of the
gastric mucosa is stimulated by acetylcholine,
histamine, and results in the activation of
protein kinases, which in turn stimulates the
H+/K+ (ATPase) proton pump to secrete
hydrogen ions in exchange for K+ into the
lumen of the stomach.

13. Inhibitors of the H+/K+-ATPase proton pump
Omeprazole bind to the H+/K+-ATPase enzyme
system (proton pump) of the parietal cell, thereby
suppressing secretion of hydrogen ions into the
gastric lumen. The membrane-bound proton pump is
the final step in the secretion of gastric acid . Four
additional PPIs are now available: lansoprazole,
rabeprazole, pantoprazole, and esomeprazole.

14. Actions:
These agents are prodrugs with an acid-resistant enteric
coating to protect them from premature degradation by
gastric acid. The coating is removed in the alkaline
duodenum, and the prodrug, a weak base, is absorbed and
transported to the parietal cell canaliculus.
There, it is converted to the active form, which reacts with
a cysteine residue of the H+/K+-ATPase, forming a stable
covalent bond.

15. Pharmacokinetics of PPIs:
For maximum effect, PPIs should be taken 30
minutes before breakfast or the largest meal of
the day.

16. ANTIACIDS
•weak bases that react with
gastric acid to form water and a
salt, thereby diminishing gastric
acidity.

17. •Commonly used antacids are salts
of aluminum and magnesium, such
as aluminum hydroxide (usually a
mixture of Al(OH)3 and aluminum
oxide hydrates) or magnesium
hydroxide[Mg(OH)2], either alone
or in combination.

18. •Systemic absorption of sodium
bicarbonate [NaHCO3] can
produce transient metabolic
alkalosis; therefore, this antacid
is not recommended for long-
term use.

19. •Adverse effects: Aluminum
hydroxide tends to be
constipating, and magnesium
hydroxide tends to produce
diarrhea.

20. H2-receptor antagonists
It inhibits gastric acid secretion, being particularly
effective against nocturnal acid secretion.
By competitively blocking the binding of
histamine to H2 receptors.These drugs are
Cimetidine , ranitidine , famotidine , and nizatidine

21. Adverse effects: The most common side effects
are headache, dizziness, diarrhea, and muscular
pain.

22. • Adverse effects may also occur in
patients with renal impairment,
caused by accumulation of
magnesium, calcium, sodium, and
other electrolytes. Excessive intake of
calcium carbonate along with calcium
foods can result in hypercalcemia.

23. •Cimetidine is the prototype histamine
H2-receptor antagonist;however, its use
is limited by its adverse effects

24. •Pharmacokinetics
•Cimetidine inhibits cytochrome P450 and can
slow metabolism (and, thus, potentiate the
action).

25. Other side effects of
Cimitidine;
gynecomastia,galactorrhea
(continuous
release/discharge of milk),
and reduced sperm count.

26. GASTRIC MUCOSAL PROTECTIVE DRUGS
•Prostaglandins
Prostaglandin E2, produced by the gastric mucosa,
inhibits secretion of HCl and stimulates secretion of
mucus and bicarbonate (cytoprotective effect).
Misoprostol, a stable analog of prostaglandin E1, as well
as some PPIs, are approved for prevention of gastric
ulcers induced by NSAIDs

27. Other Therapeutic Uses: Like other
prostaglandins, misoprostol produces uterine
contractions and is contraindicated during
pregnancy.
Adverse effects:Dose-related diarrhea and
nausea are the most common adverse effects and
limit the use of this agent.

28. •Sucralfate: By forming complex gels with
epithelial cells, sucralfate creates a physical
barrier that impairs diffusion of HCl and
prevents degradation of mucus by pepsin and
acid.

29. •Bismuth subsalicylate: antimicrobial actions,
they inhibit the activity of pepsin, increase
secretion of mucus, and interact with
glycoproteins in necrotic mucosal tissue to coat
and protect the ulcer crater.

30. SUMMARY

31. THANK YOU