17. Given 30 min before meals
Acid labile: Enteric coated tablets/ capsules
Weakly basic drugs
Accumulate & activate in canaliculi of parietal cell
Bind covalently to extracellular domain of H+ K+ ATPase
Acid secretion resumes only after synthesis of
new molecules
17
18. Not all proton pumps inactivated with 1st
dose
Reaching max potential takes up to 3–4 days
After stopping, takes 3–4 days for full acid secretion to
return
Advantages
◦ Rapid onset of action, Faster ulcer healing
Microsomal enzyme inhibitor
◦ Diazepam, phenytoin, warfarin
18
20. H2 blockers
Less potent than PPIs
Competitive blockage of H2 receptors on
parietal cell
◦ Inhibit acid secretion (70%)
Cimetidine, Ranitidine, Famotidine,
Nizatidine, Roxatidine, Loxatidine
◦ Oral, IV (Ranitidine, Famotidine)
20
21. 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, ACh,
histamine)
Avoided in pregnancy & lactation
◦ Crosses placental barrier
◦ Secreted in breast milk
21
34. Adverse effects
◦ Al salts: constipation
◦ Mg salts: diarrhea, hypermagnesemia,
◦ Ca salts: constipation, milk alkali syndrome,
rebound acidity
DI
◦ Al, Mg decreases absorption of digoxin,
tetracycline, iron salts
◦ Taken 2 hrs apart
34
35. Simethicone (Activated dimethicone)
◦ Antifoaming agent, reduces flatulence, prevents
hiccups
◦ Also used in topical skin preparations to prevent
bed sores
Sodium alginate
◦ Forms a viscous gel (raft) with gastric acid
◦ Floats, acts as mechanical barrier
35
36. • Sucralfate, Colloidal Bismuth Subcitrate (CBS),
Ranitidine Bismuth Subcitrate
Sucralfate
◦ Forms a sticky viscous gel that adheres to ulcer
base (Cytoprotective): Acts as a acid-resistant
physical barrier
◦ Promotes ulcer healing, delays gastric empting
◦ Uses: peptic ulcer, stress ulcer (1g QID)
◦ Requires pH<4 for activation
Not given along with antacids, PPIs, H2 blockers
◦ Adverse effects: Constipation, dry mouth, headache,
itching
36
37. ◦ Blackening of stool, tongue
◦ Bismuth toxicity: osteodystrophy, encephalopathy
Carbenexolone
Ulcer healing drug
Increases mucous, promotes healing, increases
endogenous PG levels
Disadv: (mineralocorticoid) retains water & salt,
high BP.
37
38. H.pylori: gram -ve bacillus, urease producing
◦ Sensitive to amoxicillin, tetracycline, clarithromycin,
metronidazole
Single drug: not used
◦ High chances of resistance
Triple/ quadruple therapy
◦ Prevents resistance, relapse
◦ Promote ulcer healing
◦ Eradicate H.pylori infection
38
39. PPI (Omeprazole 20
mg/Lansoprazole 30 mg) BD
+
Amoxicillin 1 g BD
Clarithromycin 500 mg BD
Metronidazole 400 mg BD
Total duration 14 days
Sequential therapy:
Day 1-5: Ome/lanso+amox;
Day 6-10: Ome/lanso+ Clarith +
Tinida
39
Any two
