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8/8/2019 Rx of p ulcer
http://slidepdf.com/reader/full/rx-of-p-ulcer 1/36
Treatment of PepticUlcer
8/8/2019 Rx of p ulcer
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ProglumideACh
PGE2
HistamineGastrin
Adenyl
cyclase
_+
ATP cAMP
Protein Kinase(Activated)
Ca++
+
Ca++
Proton pump
KK+ H+
Gastric acid
Parietal cell
Lumen of stomach
Antacid Omeprazole
Ranitidine
H2M3
Misoprostol
_
_
_
_
+
PGEreceptor
+
+
Gastrin
receptor +
+
+
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Action of Anti Action of Anti--Ulcer drug groupsUlcer drug groups
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Antacids
Weak bases that neutralise acid Also inhibit formation of pepsin
(As pepsinogen converted to pepsin at acidic pH)
Present day antacids : Aluminium Hydroxide
Magnesium Hydroxide
Not part of Physician prescribed regimen
OTC drug for symptomatic relief of dyspepsia
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Antacids ² cont«
Duration of action :
30 min when taken in empty stomach2 hrs when taken after a meal
Side effects : Al3+ antacids ± constipation ( As they relax gastric
smooth muscle & delay gastric emptying)
Mg2+ antacids ± Osmotic diarrhoea .In renal failure Al3+ antacid ± Aluminium toxicity
&
Encephalopathy
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Antacids ² Common additives
Simethicone ± Decrease surface tension ,therebreduce bubble formation
Added to prevent reflux .
Alginates - Form a layer of foam on top of gastric contents & reduce reflux
Oxethazaine ± Surface anaesthetic
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Antacid - Interactions
Adsorb drugs and form insoluble complexes
that are not absorbed .
Clinical importance :
Interactions can be avoided by taking
antacids 2 hrs before or after ingestion of other drugs .
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Now answer this question
Is it rational to combine aluminium hydroxide
and magnesium hydroxide in antacidpreparations ?
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Answer
Combination provides a relatively fast and
sustained neutralising capacity .
(Magnesium Hydroxide ± Rapidly acting
Aluminium Hydroxide - Slowly acting )
Combination preserves normal bowel function.
(Aluminium Hydroxide ± constipation
Magnesium hydroxide ± diarrhoea )
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H istamine H 2R eceptor Antagonist
Reversible competitive inhibitors of H2 receptor
Highly selective, No action on H1 or H3
receptors
Very effective in inhibiting nocturnal acid
secretion ( as it depends largely on Histamine )
Modest impact on meal stimulated acid
secretion (As it depends on gastrin, acetylcholine and histamine)
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H 2 Blockers²Side effects & Interactions
Extremely safe drugs
Cimetidine causes gynecomastia, galactorrhea
(as it is antiandrogenic & increases orolactin level)
Cimetidine inhibits CYP450 & increases conc.
of Warfarin, Theophylline, Phenytoin, Ethanol.
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Now answer this question
Your friend wants to take a H2 antagonist before
he takes alcohol to avoid gastric irritation .Heconsults you .Which H2 antagonist will you ask
him to take ?
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Answer :
Famotidine
Ex planation :
All H2 antagonist except famotidine inhibit
gastric first pass metabolism of ethanol andincrease its bioavailability .
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Proton Pump Inhibitors
Most effective drugs in antiulcer therapy
Irreversible inhibitor of H+ K+ ATPase
Prodrugs requiring activation in acid environment
Weakly basic drugs & so accumulate in canaliculi
of parietal cell
Activated in canaliculi & binds covalently to
extracellular domain of H+ K+ ATPase
Acid secretion resumes only after synthesis of
new molecules
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Proton Pump Inhibitors
Omeprazole 20 mg o.d.
Esomeprazole 20 - 40 mg o.d.
Lansoprazole 30 mg o.d.
Pantoprazole 40 mg o.d.
Rabeprazole 20 mg o.d.
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Now answer this question
It is given in the previous slides that the half life of
proton pump inhibitors is 1.5 hours only and
these drugs are generally given once daily. How
this can be justified ?
Answer :
P.P.I - Irreversible inhibitors of H+
K+
ATPase
(Hit and run drugs)
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P.P.I. ² Side effects & Interactions
Extremely safe drugs
Causes hypergastrinemia which leads to
carcinod tumor in rats
But no evidence of such tumors in man
Inhibit CYP 450 & hence metabolsim of
warfarin, phenytoin, etc
Pantoprazole & Rabeprazole have no significant
interactions
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Now Answer this Question
A patient comes to your clinic at midnightcomplaining of heart burn. You want to relieve his
pain immediately. What drug will you choose?
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8/8/2019 Rx of p ulcer
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Mucosal Protective Agents
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Mucosal Protective Agents
Sucralfate
Misoprostol
Colloidal Bismuth compounds
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Sucralfate
Salt of sucrose complexed to sulfated aluminium
hydroxide
In acidic pH polymerises to viscous gel that
adheres to ulcer crater
Taken on empty stomach 1 hr. before meals
Concurrent antacids, H2 antagonist avoided
( as it needs acid for activation )
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Misoprostol
PGE1 analogue
Modest acid inhibition
Stimulate mucus & bicarbonate secretion
Enhance mucusal blood flow
Approved for prevention of NSAID induced ulcer
Diarrhoea & cramping abd. pain ± 20 %
Not so popular as P.P.I are more effective & better
tolerated
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Colloidal Bismuth Compounds
Coats ulcer, stimulates mucus & bicarbonate
secretion
Direct antimicrobial activity against H.pylori
May cause blackening of stools & tongue
Not used for long periods ± bismuth toxicity
Available compounds :
Bismuth subsalicylate ± in USA
Bismuth sobcitrate ± in Europe
Bismuth dinitrate
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Now answer this question
A pregnant lady (first trimester) comes to you
with peptic ulcer disease. Which drug will youprescribe for her ?
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Answer :
Antacids or Sucralfate
Ex planation ;
H2 antagonists cross placenta and are also
secreted in breast milk. Safety of Proton pump
inhibitors not established in pregnancy.Misoprostol causes abortion .
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Can you identify these people ?
Nobel prize
Medicine ±
2005
Barry J Marshall J. Robin Warren
Discovery
of H.pylori &
its role in
ulcer
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Eradication of H .pylori
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Triple Therapy
The BEST among all the Triple therapy regimen is
Omeprazole / Lansoprazole - 20 / 30 mg bd
Clarithromycin - 500 mg bd
Amoxycillin / Metronidazole - 1gm / 500 mg bd
Given for 14 days followed by P.P.I for 4 ± 6 weeks
Short regimens for 7 ± 10 days not very effective
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Triple Therapy ² cont «
Bismuth subsalicylate ± 2 tab qid
Metronidazole - 250 mg qid
Tetracycline - 500 mg qid
Some other Triple Therapy Regimens are
Ranitidine Bismuth citrate - 400 mg bd
Tetracycline - 500 mg bd
Clarithromycin / Metronidazole - 500 mg bd
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Quadruple Therapy
Given when Triple Therapy fails
Omeprazole / Lansoprazole - 20 / 30 mg bd
Bismuth subsalycilate - 2 tabs qid
Metronidazole - 250 mg qidTetracycline - 500 mg qid
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N ow you have learnt about drugs used for treating
peptic ulcer ? Are there any drugs that can cause peptic ulcer ?
Drugs causing peptic ulcer Non Steroidal Anti Inflammatory Drugs
(NSAIDs)
Glucocorticoids Cytotoxic agents
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Stress induced ulceration after head trauma
Cushing¶s ulcer
Stress induced ulceration after severe burns
Curling¶s ulcer
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