peptic ulceration and altered bowel habits

Question 1

antacids

Answer 1

made of alkaline salts
neutralise stomach acid
bind to and inactivate pepsin

adverse effects:
constipation
diarrhoea

Question 2

pepsin

Answer 2

protein digesting enzyme

Question 3

H2-receptor antagonist

cimetidine, ranitidine

Answer 3

competitively block the action of histamine on the parietal cell

avoid cimetidine in patients on warfarin, phenytoin, theophyline

Question 4

PPIs

omeprazole, lansoprazole

Answer 4

irreversible inhibition of H+/K+ ATPase responsible for secretion from parietal cells

interactions with clopidogrel

Question 5

H. pylori eradication

Answer 5

triple therapy:
PPI, amoxicillin, clarithromycin/metronidazole

quad therapy:
omeprazole, 2 ABx (tetracycline and metronidazole) and bismuth chelate

Question 6

bulk forming laxatives

Answer 6

increase volume of non-absorbable material in the gut
distend the colon and stimulate peristalsis
take with plenty of fluid and may take a few days to act

C/I: dysphagia, obstruction, colonic atony, faecal impaction

eg: bran powder, fybogel

Question 7

osmotic laxatives

Answer 7

increase water content in the bowel vis osmosis
distend the colon and stimulate peristalsis

C/I: intestinal obstruction

eg: lactulose, macrogol (movicol)

Question 8

stimulant laxatives

Answer 8

increae peristalsis
increase water and electrolyte secretion by the mucosa

C/I: obstruction, acute colitis

eg: senna

Question 9

faecal softeners

Answer 9

promote defecation by softening or lubricating the stool
particularly useful for fissures

C/I: not for children under 3yo

eg: arachis oil, liquid paraffin (but not for a prolonged period - anal seepage, lipoid pneumonia)