gastric acid disorders and ulceration

Question 1

dyspepsia and when to refer

Answer 1

range of upper GI symptoms - upper abdominal pain, heartburn, gastric reflux, bloating, N&V

refer:
- GI bleed
- unintentional weight loss
- >55 years age
- dysphagia

Question 2

drug treatment

Answer 2

antacids may be used for short term symptom control - not for long term

uninvestigated dyspepsia
- ppi first for 4 weeks
- test for H.pylori if ppi didn’t work - treat if positive

functional dyspepsia (investigated but no cause - chronic symptoms)
- test for h.pylori - treat if positive
- if not positive - then 4 weeks of ppi or H2RA

Question 3

h.pylori infection and management

Answer 3

most common cause of peptic ulcers
increases risk of peptic ulcer and bleeding, associated with gastric cancer

test and treat strategy to confirm presence of h.pylori
urea 13c breath test or SAT - stool helicobacter antigen test
- PPIs stopped 2 weeks before test
- antibiotics stopped 4 weeks before test
as this can give false negatives

triple therapy - ppi + 2 antibiotics
ppi - BD
amoxicillin - 1g BD
clarithromycin - 500mg BD
metronidazole - 400mg BD

FOR 7 DAYS

Question 4

GORD and treatment

Answer 4

same referral as dyspepsia
chronic condition where there’s a reflux of gastric contents (acid, bile, pepsin) back into the oesophagus
- causes heartburn and acid regurgitation
- other symptoms - chest pain, hoarseness, cough, wheezing, dental erosion if acid reaches throat

GORD increased by: fatty foods, pregnancy, obesity, drug S.Es, stress, anxiety, smoking, alcohol

treatment: lifestyle advice first
- healthy eating, weight loss, smoking cessation, reduce alcohol

first review medications which might exacerbate GORD - arbs, ccbs, bb, benodiazepines, anti-cholinergics, steroids, NSAIDs

undiagnosed GORD - treat same as uninvestigated dyspepsia - PPI for 4 weeks

endoscopy confirmed GORD - PPI for 4-8 weeks, if no response try H2RA

GORD in pregnancy:
- diet and lifestyle - 1st line
- antacid or alignate
- omeprazole or ranitidine

Question 5

antacids

Answer 5

magnesium containing - laxative
aluminium containing - constipation
calcium containing - rebound acid secretion
simeticone (anti-foaming agent) + antacids - relieve flatulence

alginates + antacids - increase viscosity of stomach contents - prevents acid going back to oesophagus

Question 6

antacids interactions

Answer 6

increase stomach pH - alkaline - increases breakdown of enteric coated tabs/caps - before reaching intestine

antacids have high sodium - check sodium content of antacid - don’t take with lithium or in hypertension
- low sodium antacid = co-magaldrox

antacids shouldn’t be taken with certain drugs due to impairing absorption e.g. bisphosphonates, ciprofloxacin, tetracyclines

Question 7

ppi imp points

Answer 7

omeprazole, esomeprazole, lansoprazole, rabeprazole

MHRA warning - low risk of subacute cutaneous lupus erythematosus

increases risk of fractures/osteoporosis - due to hypomagnesium

increases risk of C.difficile

masks symptoms of gastric cancer

interactions:
- clopidogrel + eso/omeprazole - reduces clopidogrel plasma level
- clopi is prodrug activated by CYP2C19
- esomep and omep are CYP2C19 inibitors
switch to lansoprazole

due to being enzyme inhibitor - increases conc of methotrexate, warfarin, phenytoin, digoxin

Question 8

h2 receptor antagonists imp points

Answer 8

ranitidine, cimetidine, famotidine, nizatidine

caution - may mask symptoms of gastric cancer

s.e - diarrhoe, headache, rash, dizziness, tiredness

cimetidine - CYP450 inhibitor
H2RAs interact with azole antifungals (ketoconazole, miconazole, clotrimazole) - reduce their absorption