Upper GI drugs Flashcards
Simple explanation of GORD
imbalance between damaging and protective mechanisms
How do antacids work?
brief neutralisation of gastric acid
rapid onset bu transient
When are antacids used?
GORD
dyspepsia
Dyspepsia lay mans term
indigestion
Antacids adverse effects
milk alkali syndrome (in high doses)
aluminium containing = constipation
magnesium-containing = diarrhoea
carbonate compounds release CO2 –> belching
How does alginic acid work and what is a common brand name for it?
inert raft on gastric contents
protects against reflux
combined with antacids
gaviscon
Name some H2 receptor antagonists
cimetidine
nizatidine
famotidine
How do H2 receptor antagonists work
reduce basal and stimulated acid secretion
reduce pepsin secretion
H2 receptor antagonists indications
duodenal ulcer
gastric ulcer
GORD symptomatic relief
Adverse effects of H2 receptor antagonists
diarrhoea
headache
confusion in elderly
Cimetidine adverse effects
anti-androgen = gynaecomastia
inhibits P450 = enhances warfarin, theophylline, tolbutamide
How do PPIs work?
irreversibly inhibit the final common pathway of H+ secretion
Name some PPIs
omeprazole
lansoprazole
pantoprazole
esomeprazole
Metabolism of PPIs
via P450 system
PPI adverse effects
diarrhoea
headache
infectious gastroenteritis (reduce bacteria killing)
hypergastrinaemia and acid rebound
impaired calcium and magnesium absorption
When should PPIs be stopped in hospital?
when on broad spectrum abx
PPIs should be stopped to prevent C.Diff infection
Indications for parenteral acid suppression
prevention of aspiration during anaesthesia
stress ulcer prophylaxis in ITU
peptic disease and unable to take oral treatment for 5 days
post-endoscopic in selected GI haemorrhage patients
non-responsive zollinger ellison syndrome
What is the best medical treatment for GORD?
PPI
(better than H2RA)
Surgical management of GORD
laparoscopic fundoplication
How should acid suppression be approached in peptic ulcer?
remove aetiological factors (NSAIDs, H pylori)
PPI
How is misoprostol used for the upper GI tract?
prostaglandins make mucosa healthy
PGE1 analogue
inhibits acid secretion
increases gastric mucus production
increases mucosal blood flow
(can be used for pts on NSAIDs)
Misoprostol adverse effects
diarrhoea
uterine contractions - avoid in pregnancy and young women
menorrhagia + post-menopausal bleeding
How does sucralfate help in peptic ulcers?
coats ulcer base
forms cover on ulcers
?stimulates prostaglandin synthesis
prevents diffusion of acid
Bismuth adverse effects
black stools
black tongue
minimal absorption
Bismuth OTC name
Peptobismol
