GI Pharmacology Flashcards
What class of drug is Omeprazole?
Proton pump inhibitor
What are some common indications for Omeprazole?
Indigestion, heartburn and acid reflux
What is the mechanism of action of Omeprazole?
Irreversibly inhibit the H+/K+ ATPase in gastric parietal cells.
Final stage in the pathway- very significant reduction in acid secretion
What are the adverse effects of Omeprazole?
GI disturbance, abdominal pain, constipation, diarrhoea, headache, dizziness, drowsiness and confusion
What are the drug-drug interactions of Omeprazole?
Omeprazole is a CYP inhibitor- reduced clopidogrel action
PPIs can increase effects of warfarin and phenytoin
How can you remember Omeprazole?
what class of drug is loperamide
it is a opioid receptor antagonist
how do opioid receptor antagonists work in treating diarrhoea
- specific to U receptors in the myenteric plexus so reduces peristalsis
- decreases muscle tone (circular and longitudinal)
- suppresses the gastrocolic reflexes
what are some other opioid receptor antagonists
- codine or morphine
what are some side effects of loperamide
- nausea and vomiting
- addiction
-sedating - paralytic ileus
what class is lactulose or movicol
osmotic laxative
how does an osmotic laxative work
increases the amount of water in the bowels by drawing fluid into the bpwels
what are some side effects of osmotic laxatives
N+V
abdo pain
what class of drug is Senna/Bisacodyl
stimulant laxative
how does a stimulant laxative work?
increases the intestinal motility and acts as a stool softener
it increases the CFTR channels so increases Cl in the bowels and increases water
what is a side effect of stimulant laxative
albuminuria
what are some foods that worsen constipation
white bread and white rice
what class of drug are methylcellulose and ispaghula
bulk forming laxative
how do bulk forming laxatives work
they increase there fibre content in the stock
what class of drug is docusate sodium
stool softener
how do stool softens work
increase penetration of liquid into stool
what class of drug is alginic acid
compound alginate
how does alginic acid work
combines with bicarbonate to inhibit reflux
what are some indications of alginic acid
GORD
peptic ulcer
heart burn
