Gastrointestinal Flashcards
Hyoscine butylbromide
(Antimuscarinics)
Irritable bowel syndrome (for its antispasmodic effect)
(Acetylcysteine)
Paracetamol metabolised into N-acetyl-p-benzoquione imine (NAPQI). NAPQI is hepatotoxic, and detoxified with conjugation with glutathione. Acetylcysteine replenishes glutathione supple in paracetamol poisoning.
Also has antioxidant effects. Also breaks disulphide bonds in mucus to decrease viscosity.
Antidote for paracetamol poisoning
Prevent renal injuring from radiographic contrast
Reduce viscosity of respiratory secretions
(Alginates and antacids)
Antacids buffer stomach acids. Alginates increase viscosity of stomach content, preventing reflux.
Gaviscon
(Alginates and antacids)
Gatro-oesophageal reflux disease
Dyspepsia
Antacids
(Alginates and antacids)
Gatro-oesophageal reflux disease
Dyspepsia
(Aminosalicylates)
Mechanism unknown, but has anti-inflammatory and immunosuppressive effects.
✖Aspirin hypersensitivity
Mesalazine
(Aminosalicylates)
+ corticosteroids to treat ulcerative colitis
Sulfasazine
(Aminosalicylates)
Rheumatoid arthritis
(Antiemetics, dopamine D2-receptor antagonist)
Vomiting centre in medulla receives input from chemorecpetor trigger zone, solitary tract nucleus, vestibular system and higher neurological centres. D2 receptor is main receptor in chemoreceptor trigger zone. Dopamine also has pro-kinetic effect in gut, promoting gastric emptying
✖Neonates
✖Cardiac conduction abnormalities
✖Intestinal obstruction/perforation
Metoclopramide
(Antiemetics, dopamine D2-receptor antagonist)
Treatment of nausea and vomiting
Domperidone
(Antiemetics, dopamine D2-receptor antagonist)
Treatment of nausea and vomiting
(Antiemetics, histamine H1-receptor antagonists)
Histamine (H1) and acetylcholine (muscarinic receptors) predominate in vomiting centre as well as communication with vestibular system. Drugs blocking H1 receptors useful in treating nausea and vomiting especially from motion and vertigo.
Cyclizine
(Antiemetics, histamine H1-receptor antagonists)
Nausea and vomiting especially due to motion sickness or vertigo
Cinnarizine
(Antiemetics, histamine H1-receptor antagonists)
Nausea and vomiting especially due to motion sickness or verticgo
Promethazine
(Antiemetics, histamine H1-receptor antagonists)
Nausea and vomiting especially due to motion sickness or vertigo
(Antiemetics, serotonin 5-HT3-Receptor antagonists)
High number of serotonin receptors in chemorecptor trigger zone of medulla and in gut, released in response to emetogenic stimuli. Serotonin antagonists effective in nausea and vomiting caused by nausea inducing chemicals and visceral stimulation (e.g. gut infection, radiotherapy)
Ondansetron
(Antiemetics, serotonin 5-HT3-Receptor antagonists)
Prophylaxis and treatment of nausea and vomiting
Granistron
(Antiemetics, serotonin 5-HT3-Receptor antagonists)
Prophylaxis and treatment of nausea and vomiting
(Anti-motility drugs)
Agonist of opioid receptors in gut. Increases non-propulsive contractions but decrease propulsive/peristaltic contractions. Transit of bowel content slowed and anal sphincter tone increased.
Loperamide
(Anti-motility drugs)
Symptomatic treatment of diarrhoea
Codeine phosphate
(Anti-motility drugs)
Symptomatic treatment of diarrhoea
(Azathioprine)
Prodrug that is metabolised into active form (6-mercaptopurine) Inhibit synthesis of purines and inhibit DNA and ribonucleic acid replication. Lymphocytes dependant on purine synthesis
Maintenance of Crohn’s disease remission and ulcerative colitis
Rheumatoid arthritis and autoimmune conditions not responding to corticosteroids
Prevent organ rejection
(Calcium and vitamin D)
Positive calcium balance via diet or supplements reduce rates of bone loss. In chronic kidney disease impaired phosphate excretion and reduced activation of vitamin D causes hyperphosphataemia and hypocalcemia. Oral calcium binds to phosphate in gut; alfacalcidol provides vitamin D. In hyperkalaemia, calcium raises myocardial threshold potential, reducing risk of arrhythmia
✖Hypercalcaemia
Calcium carbonate
(Calcium and vitamin D) Osteoporosis Chronic kidney disease Severe hyperkalaemia Hypocalcaemia
Calcium gluconate
(Calcium and vitamin D) Osteoporosis Chronic kidney disease Severe hyperkalaemia Hypocalcaemia
Colecalciferol
(Calcium and vitamin D) Osteoporosis Chronic kidney disease Severe hyperkalaemia Hypocalcaemia Vitamin D deficiency
Alfacalcidol
(Calcium and vitamin D) Osteoporosis Chronic kidney disease Severe hyperkalaemia Hypocalcaemia
(Histamine H2-receptor antagonist)
Histamine receptor antagonists reduces gastric secretion. Proton pumps regulated by histamine. Partially suppresses acid production as there are other means of stimulation. PPIs offer more complete suppression
Ranitidine
(Histamine H2-receptor antagonist)
Peptic ulcer disease
Gastro-duodenal reflux disease and dyspepsia
(Osmotic laxatives)
Osmotically active substances are not digested or absorbed. Remains in lumen and hold water. Lactulose in particular reduces ammonia absorption by increasing gut transit and acidifying stool that reduces numbers of ammonia producing bacteria. Useful in liver failure + encephalopathy
✖Intestinal obstruction
Lactulose
(Osmotic laxatives)
Constipation
Bowel preparation
Hepatic encephalopathy
Macrogol
(Osmotic laxatives)
Constipation
Bowel preparation
Phosphate enema
(Osmotic laxatives)
Constipation
Bowel preparation
(Stimulant laxatives)
Increases water and electrolyte secretion into lumen to stimulate peristalsis
✖Intestinal obstruction
Senna
(Stimulant laxatives)
Constipation
Glycerol suppositories
(Stimulant laxatives)
Faecal impaction
Bisacodyl
(Stimulant laxatives)
Constipation
Docusate sodium
(Stimulant laxatives)
Constipation
(Proton pump inhibitors)
Irreversibly inhibits H+/K+ ATPase in gastric parietal cells.
Lansoprazole
(Proton pump inhibitors)
Peptic ulcer disease
Symptomatic treatment of dyspepsia and GORD
+ antibiotic therapy in H. pylori eradication
Omeprazole
(Proton pump inhibitors)
Peptic ulcer disease
Symptomatic treatment of dyspepsia and GORD
+ antibiotic therapy in H. pylori eradication
Pantoprazole
(Proton pump inhibitors)
Peptic ulcer disease
Symptomatic treatment of dyspepsia and GORD
+ antibiotic therapy in H. pylori eradication
