GI drugs Flashcards
Which GI side effects are associated with which antacids ? (2)
Magnesium containing are laxatives
Aluminium are constipating
Combination is best.
Why is cimetidine rarely used? (1)
Enzyme inhibitor
What is the mechanism of omeprazole? (1)
PPI
inhibits the hydrogen-potassium ATP enzyme pump of the gastric parietal cell.
Which PPI and anti-platelet should be avoided together? (1)
Omeprazole and clopidogrel.
When are laxatives contraindicated? (2)
In paralytic ileus, intestinal obstruction and perforation, severe inflammatory conditions eg IBD
Name 3 types of laxatives. (3)
Osmotic eg lactulose, macrogol.
Bulk forming eg ispaghula husk
Stimulant eg senna, docusate.
When should anti-emetics be prescribed? (1)
Once cause of vomiting is known, so that therapeutic agent can be chosen.
Which anti-histamines can be used to treat nausea and vomiting? (1)
H1 receptor antagonists. eg cyclizine, cinnarizine.
Used to treat motion sickness and vestibular disorders.
Name a phenothiazine. (1)
How does it work? (1)
Chlorpromazine, Prochlorperazine.
Dopamine antagonists, act centrally by blocking the chemoreceptor trigger zone in the fourth ventricle.
How do metoclopramide and domperidone work? (2)
Block dopamine receptors and inhibit dopaminergic stimulation of the chemoreceptor trigger zone in the fourth ventricle.
What side effect of metoclopramide cautions its use in Parkinson’s patents? (1)
Extrapyramidal side effects.
What type of drug is ondansetron? (2)
5HT3 receptor antagonist.
Blocks the 5-HT-3 receptors in the chemoreceptor trigger zone in the fourth ventricle and the gut.
