5. SYMPTOMS AND SIGNS
• Abdominal pain
• Water brash
• Nausea and vomiting
• Loss of appetite and weight loss
• Haematemesis
• Melaena
• Heartburn and gastro esophageal reflux
6. PATHOPHYSIOLOGY
Mechanism of gastric acid secretion
• H+K+ATPase (proton pump)-secretes H+
ions in the apical canaliculi of parietal cells
• Proton pump is activated by-
- Histamine- H2 receptors
- Ach- M3 receptors
- Gastrin-G receptors
7.
8.
9. PROTECTIVE BARRIER
• Mucus secreted by mucus secreting cells
• Bicarbonate ions
• Role of prostaglandins
-Reduces acid and pepsin
secretions(PGE2)
-Increases mucus secretion and mucosal
blood flow(PGI2)
13. H2 ANTAGONISTS
THESE ARE THE FIRST CLASS OF HIGHLY EFFECTIVE
DRUGS FOR ACID – PEPTIC DISEASE
SOME OF THE H2 ANTAGONISTS ARE
CIMETIDINE
RANITIDINE
FAMOTIDINE
ROXATIDINE
LOXATIDINE
NAXITIDINE
31. CIMETIDINE
H2 ANTAGONISTS EFFECTIVE AT INHIBITING
NOCTURNAL ACID SECRETIONS WHICH
DEPENDS WHOLLY ON HISTAMINE
MODEST IMPACT ON MEAL STIMULATED ACID
SECRETIONS
THUS BLOCK > 90% NOCTURNAL ACID AND 60-
80% DAY TIME ACID SECRETIONS
32. ADVERSE DRUG REACTIONS
HEADACHE, DIZZINESS, TIREDNESS,
CONFUSION,BOWEL UPSET, ETC
ANTIANDROGENIC ACTION – INCREASES
PROLACTIN
HIGH DOSES PRODUCE
GYANAECOMASTIA, LOSS OF LIBIDO ,
IMPOTENCE
REVERSIBLE ON STOPPING DRUG
THUS OUTDATED NOWADAYS
33. USES
PEPTIC ULCER DISEASE
400mg bd or 800mg ORAL at bedtimes
STRESS ULCER PROPHYLAXIS :50mg/hr iv
ZOLLINGER- ELLISON SYNDROME
GASTRO OESOPHAGEAL REFLUX DISEASE
PROPHYLAXIS OF ASPIRATION PNEUMONIA
OTHER USES:ADJUVANT IN URTICARIA
DOSAGE : AVAILABLE AS 200mg ,400mg, 800mg tab
34. RANITIDINE
OVER THE COUNTER DRUG,
PREFFERED DRUG OVER CEMITIDINE.WHY?
5 TIMES MORE POTENT
NO ANTIANDROGENIC ACTION
LESS PERMEABLE INTO BRAIN
DOES NOT SIGNIFICANTLY AFFECT HEPATIC METABOLISM
COMBINED WITH BISMUTH SALT TREAT H.PYLORI INFECTION
SIDE EFFECTS – IRREGULAR HEART BEATS , YELLOWING OF
SKIN AND EYES, DIZZINESS, HEADACHE,ETC
35. DOSAGE
GERD- ZANTAC 150mg/10ml SYRUP TWICE DAILY
ACTIVE DU- ZANTAC 150mg/10ml SYRUP TWICE DAILY OR
300mg ONCE DAILY AT BEDTIME
ZE SYNDROME-150mg/10ml TWICE DAILY
PAEDIATRIC – DU AND GU -2-4mg/kg TWICE DAILY MAX
300mg/day
GERD 5-10mg/kg/day AS TWO DIVIDED DOSES
WITH IMPAIRED RENAL FUNCTION-
CREATINE CLEARANCE <50ml/min THEN 150mg/10ml SYRUP
EVERY 24 HRS
36. OTHERS
FAMOTIDINE- LONGER DURATION OF ACTION. TRADE
NAME- PEPCID
5-8 TIMES MORE POTENT THAN RANITIDINE, T1/2 2.5-3.5 HRS
NO ANTIANDROGENIC EFFECT
MORE SUITABLE FOR ZE SYNDROME
PEPCID- 10,20 AND 40mg TABLETS
ROXATIDINE – TWICE AS POTENT , LONGER ACTING
NO ANTIANDROGENIC OR CYTOCHROMEP450 INHIBITION
LOXATIDINE:recent
38. PROTON PUMP INHIBITORS
• PPIs are the drugs which suppress the
gastric acid secretion by reacting
covalently with H⁺K⁺ATPase enzyme and
thus inactivating them irreversibly .
40. Mechanism of action of PPIs
(taking omeprazole as a prototype)
From the blood
Parietal cells
At pH<5 it rearranges cationic forms -
sulphenic acid
sulphenamide
React with H⁺K⁺ATPase enzyme and inactivate it
irreversibly
41. • Acid secretion resumes only when new
H⁺K⁺ATPase molecules are synthesized .
• Bioavailability of all PPIs is reduced by
food , they should be taken in empty
stomach followed by 1 hour later meal to
activate the H⁺K⁺ATPase and make it
more susceptible to the PPI.
46. 3.LANSOPRZOLE –
• More potent ,
• high oral availablity ,
• longer t ½ ,faster onset of action than
omeprazole .
47. 4.PANTOPRAZOLE-
• Newer
• More acid stable
• Available for I.V. administration
• Particularly employed in bleeding peptic
ulcer and prophylaxis of acute stress
ulcers.
49. ANTICHOLINERGICS
The anti muscarinic drugs were used mainly to treat
peptic ulcers until the introduction of the H2
receptor blocking agents, but now rarely used.
• PIRENZEPINE – selective M1 anti cholinergic.
• ADVERSE EFFECTS –
– Blurred vision
– Dry mouth
– Urine retention
50. ANTACIDS
STOMACH ACID NEUTRALISER
TREAT DYSPEPSIA OR HEARTBURN
MECH.-PERFORM NEUTRALISATION REACTION ie BUFFER
GASTRIC ACID RAISING pH >4
INHIBIT ACTIVITY OF PEPSIN WHICH IS IRRITATING TO
THE STOMACH
INCREASE L.E.S TONE SO THAT REFLUX
IS REDUCED
RELIEF OCCURS WITH IN 5-15 min
DURATION OF RELIEF LAST FOR 1-3 HRS
52. ANTACID
COMBINATIONS
COMBINATIONS OF ANTACIDS FREQUENTLY USED
SINGLE ANTACID NOT SATISFACTORY
a) FAST (Mg.hydrox.) AND SLOW (Alum.hydrox.) YIELD
PROMPT AND SUSTAINED EFFECT
b) Mag. SALTS (LAXATIVE) AND Alum. SALTS
(CONSTIPATING)- BOWEL MOVEMENT LEAST AFFECTED
d) GASTRIC EMPTYING- Alum. SALTS DELAY IT AND Mag.
OR Cal. SALTS TEND TO HASTEN IT
c) DOSE OF INDIVIDUAL COMPONENT IS
REDUCED.THEREFORE SYSTEMIC TOXICITY IS MINIMISED.
53. CONTD.
SOMETIMES COMBINED WITH ANTIFLATULENT
COMP.(DIMETHICONE, SIMETHICONE) OR
ANAESTHESIA
AVAILABLE COMBINATIONS ARE :
DIGENE:
Alum.hydrox.300mg.Alum.silicate50mg,Mag.
hydrox.25mg,methyl polysilox 10mg/TAB
DIGENE GEL:
Mag.hydrox.185mg Alum.hydrox.gel830mg,
Sodium carboxymethyl cellulose100mg
Methylpolysilox.25mg PER 10ml SUSP.
55. H. Pylori
• Gram –ve bacillus
• Has high urease activity, produces
ammonia
• Major factor in pathogenesis of peptic
ulcer
• Almost all duodenal ulcers and 70% of
gastric ulcers show presence of H. pylori
• It also causes chronic
gastritis,dyspepsia, gastric lymphoma
and gastric carcinoma
56. PREFERRED THERAPIES FOR H.
PYLORI INFECTION
• Twice a day PPI or Ranitidine bismuth citrate
• Triple therapies –
A PPI or 400 mg of ranitidine or bismuth citrate twice
a day
Plus 2 of: Amoxicillin 1g; Clarithromycin 500 mg; or
Metronidazole 500 mg (each twice a day)
• Quadruple therapy –
A PPI twice a day
Tetracycline hydrochloride 500 mg, 4 times/day
Bismuth subcitrate 120 mg, 4 times/day
Metronidazole 500 mg, 3 times/day
