GI System Flashcards
What is the drug class for Gaviscon and Peptac?
Alginates and Antacids
how does Gaviscon work?
Alginates - forms a raft (increase liquid viscosity) to prevent any reflux and mucosal damage
Antacids - buffers acids
Indications for Gaviscon and Peptac?
GORD and dyspepsia
Contra-indication for Gaviscon and Peptac?
Do not give with thickened milk as this can cause stomach discomfit, bloating etc.
Preparation with Na+/K+ for pt with fluid overload/hyperkalaemia
Sucrose - for diabetes pts
What are the main component of Gaviscon?
Aluminium hydroxide and magnesium trisilicate
Side effect for alginate and antacid?
Aluminium - cause constipation
Magnesium - cause diarrhoea
interaction of alginate and antacids?
alginates - lower drug absorption
antacids - lower drug serum conc. (cause urine to become more alkaline - more aspirin/lithium excretion)
possible interact with ACEi, cephalosporins, ciprofloxacin, tetracyclines, bisphsphonates, digoxin, levothyroxine, PPis
where is alginates and antacids eliminated
kidney
what advice can you give pts who are taking gaviscon
- take after meals, before bed and following symptoms
- leave 2 hrs before taking any other drugs
What is the drug class for Ranitidine
H2-receptor antagonists
What is the MOA of Ranitidine?
antagonist of H2 receptors (limit the numbers of H2 receptors which can be bind by histamine)
Histamine –> H2 receptors –> Proton Pump –> H+
so eventually stops the production of gastric acid
Where is histamine produced in the stomach
paracine cells
Where is H2 receptors located in the stomach?
parietal cells
Main indication for H2 receptor antagonist
GORD, Dyspepsia, peptic ulcer
What is the contra-indication for Ranitidine
renal pts (eliminated in kidney), disguise symptoms of stomach cancer
What is some of the side effect of Ranitidine
Diarrhoea, headache, dizziness
What is the possible interaction of Ranitidine
N/A
Where is Ranitidine eliminated?
kidneys
What are some drugs of the family of Proton Pump Inhibitors
Lansoprazole, Omeprazole, pantoprazole
What is the MOA of PPI
Inhibits the proton pump (H+/K+ ATPase) presnet in the parietal cells of the stomach and almost permanently stops the production of stomach acids (unlike Ranitidine)
What is the downfall of Ranitidine
not complete stop to the production of stomach acids as there are other ways to stimulate proton pumps (unlike PPI eg Lansoprazole, Omeprazole, Pantoprazole)
What are the main indication for PPI?
peptic ulcer disease (mostly NSAID associated)
H.pylori infection (used in combination with other antibiotics)
GORD
Dyspepsia
Contraindication for PPI?
Disguise stomach cancer Osteoporotic pts (increase risk of fracture)
Side effect for PPI?
Gi disturbance ( diarrhoea, constipation, nausea)
headache
Increase C.diff infection (as stomach acidity is reduced)
Hypomagnesaemia ( can lead to tetany and ventricular arrhythmia)