CHAPTER 1 –GASTROINTESTINAL SYSTEM
1.1 DYSPEPSIA AND GASTRO-OESOPHAGEAL REFLUX DISEASE
Dyspepsia
o Pain, fullness, early satiety, bloating and nausea
o Can occur due to duodenal and gastric ulcers and gastric cancer
o Use antacids to alleviate symptoms and also H2 Receptor antags and PPIs may also be effective
ALARM FEATURES
o Bleeding
o Dysphagia
o Recurrent vomiting
o Weight loss
o 55+
GORD
o Associated with heartburn, acid regurgitation, difficulty swallowing, oesophageal inflammation,
ulceration and stricture formation may occur
o Lifestyle changes:
Avoidance of excess alcohol and of aggravating foods such as fats
Weight reduction
Smoking cessation
Raising head of bed
o Usually use antacid and alginates, histamine H2-receptor antagonists PPIs (more effective than H2-
receptor antagonists)
1.1.1 Antacids and Simeticone
Aluminium and magnesium containing antacids – being relatively insoluble in water, are long-acting if
retained in stomach
Magnesium
o LAXATIVE EFFECTIVE
Aluminium
o CONSTIPATING EFFECT
Sodium bicarbonate – should not be pxbed alone for dyspepsia and should avoid in pts on Na + restriction
Bismuth-containing antacids are not recommended as absorbed bismuth can be neurotoxic
o Can cause encephalopathy, and also cause constipation
o Calcium containing antacids can induce rebound acid secretion, prolonged high doses can cause
hypocalcaemia and alkalosis and can ppt milk-alkali syndrome
Simeticone
o Antifoaming to relieve flatulence
o Preps can be useful for relief of hiccup in palliative care
COUNSELLING: antacids should preferably not be taken at same time as other drugs since they may impair
absorption and they also damage ENTERIC COATINGS designed to prevent dissolution in the stomach
1.1.2 Compound Alginates And Proprietary Indigestion Preparations
Alginates taken in combi with antacids increase viscosity of stomach contents and can protect the
oesophageal mucosa from acid reflux
Some alginate containing preparations form a viscous gel (‘raft’) that floats on surface of stomach contents
thereby decreasing symptoms of reflux
, 1.2 ANTISPASMODICS AND OTHER DRUGS ALTERING GUT MOTILITY
These drugs include antimuscarinic compounds and drugs believed to be direct relaxants of intestinal
smooth muscle
ANTIMUSCARINICS
o Reduce intestinal motility
o Management of IBS and diverticular disease
o Drugs used for GI smooth muscle spasm:
Atropine, dicycloverine, propantheline and hyoscine butylbromide
o CAUTIONS:
Down’s syndrome, children and elderly, GORD, diarrhoea, UC, MI, HTN, pregnancy
o CONTRAINDICATED:
Myasthenia gravis, Paralytic ileus, pyloric stenosis and prostatic enlargement, closed angle
glaucoma
o SIDE EFFECTS: Constipation, urinary urgency and retention, dilation of pupils, photophobia, flushing
and dryness of skin
OTHER ANTISPASMODICS
o Alverine, Mebevrine, Peppermint Oil
Direct relaxants of intestinal smooth muscle and may relieve pain in IBS and diverticular
disease
o AVOID: paralytic ileus
o Peppermint oil
MINTEC: Is Enteric Coated
COLPERMIN: Modified release AND EC
These caps should not be broken or crushed as can irritate oesophagus
MOTILITY STIMULANTS
o Metoclopramide and Domperidone
Dopamine receptor antagonists – stimulate gastric emptying and small intestinal transit
1.3 ANTISECRETORY DRUGS AND MUCOSAL PROTECTANTS
Helicobacter Pylori
Presence of bacteria should be confirmed before commencing tx
TREATMENT: ONE WEEK TRIPLE THERAPY – PPI, Clarithromycin and Metronidazole or Amoxicillin
1.3.1 H2 Receptor Antagonists
Heal gastric and duodenal ulcers by reducing gastric acid output as a result of histamine H 2 blockade
CIMETIDINE: ENZYME INHIBITOR
1.3.3 Chelates And Complexes
Tripotassium dicitratobismuthate = bismuth chelate effective in healing gastric and duodenal ulcers
o Bismuth content is low but absorption has been reported, encephalopathy has not
o COUNSELLING: Swallow with ½ a glass of water and may darken tongue and colour faeces
Sucralfate
o Act protecting mucosa from acid-pepsin attack in gastric and duodenal ulcers
o Complex of aluminium hydroxide and sulphated sucrose but has minimal antacid properties
o SIDE EFFECT: Bezoar formation – therefore caution in seriously ill patients, esp with pts whose
condition cause them to have delayed gastric emptying