GIT drugs Flashcards
what is ranitidine?
H2 receptor antagonist
what is H2 receptor antagonist contraindicated in?
renal failure
what is an adverse effect of H2 receptor antagonist?
gynaecomastia, impotence, interaction with CYP450
what drug irreversibly inactivates H+/K+ ATPase proton pump?
PPI (esomeprazole)
why should other acid suppressing agents (eg. antacids) not be co-administered with PPIs?
PPIs are only activated in acidic environment
which drugs are enteric coated?
PPIs
what drugs adhere to ulcers, acting as protective barrier against aggressive luminal factors (eg. acid, pepsin, bile salts)?
sucralfate and bismuth
what drug is a complex of aluminium hydroxide and sulfated sucrose?
sucralfate
what is sucralfate contraindicated in?
renal failure
what adverse effect can sucralfate cause?
constipation
what is an example of a prostaglandin analogue?
misoprostol
what is misoprostol contraindicated in?
pregnancy
which drug has moderate direct bactericidal activity against H.pylori?
bismuth
which drug cause blackening of stools and tongue?
bismuth
what drugs are part of the triple therapy against H. pylori?
PPI + amoxicillin + clarithromycin
what drugs are part of the quadruple therapy against H. pylori?
PPI (Esomeprazole) + bismuth + metronidazole + tetracycline
what type of laxatives involve the formation of bulky hydrated mass that draws water in and promotes peristalsis?
bulk laxatives
what laxatives are contraindicated in children and patients with poor renal function?
osmotic laxatives
what is senna?
stimulant laxatives
what is the MOA of stimulant laxatives?
stimulate myenteric plexus –> increase peristalsis and defecation
what is the first-line drug indication for children with constipation?
sodium docusate
what is the MOA of sodium docusate?
contains surfactant –> decreases surface tension of water on stools –> water can enter stools more easily
what drug is useful in patients where straining should be avoided?
sodium docusate (faecal softener)
what is metoclopramide?
D2 receptor antagonist
what is the MOA of loperamide?
activates mu-receptors –> release of inhibitory neurotransmitters –> decreased activity of myenteric plexus –> decreased peristalsis
which drug is indicated in both constipation and vomiting?
metoclopramide
what is promethazine?
H1 receptor antagonist
what is ondansetron?
5HT3 antagonist
what is promethazine usually used for?
motion sickness and morning sickness in pregnancy
which anti-emetic can cross BBB and exert CNS side effects?
promethazine (h1 receptor antagonist)
metoclopramide (D2 receptor antagonist)
