Clinical pharmacology of the alimentary system Flashcards
3 types of acid suppression drugs
alginates (gaviscon)
H2 receptor antagonists (Ranitidine)
proton pump inhibitors (omeprazole)
drugs affecting GI motility
anti-emetics
anti-muscarinics
anti-motility
3 categories of alimentary drugs are
acid suppression
drugs affecting the GI motility
laxatives
IBD drugs
drugs affecting intestinal secretions
drugs for IBD
aminosalicylates
corticosteroids
immunosuppressants
biologics
acid suppression is done by 2 types of drugs
antacids (maalox)
alginates (gaviscon)
antacids
continuous magnesium or aluminium to neutralise gastric acid
alginates
form a viscous gel the floats on stomach contents and reduced reflux
h 2 receptor antagonists
acid suppression
block histamine receptor thereby reducing acid secretion
used in GORD
proton pump inhibitors
acid suppression
block proton pump and thereby reduce acid secretion
used in GORD
pro kinetic agents increase what?
gut motility and gastric emptying
mechanism of action is unclear but the parasympathetic NS is involved
vomitting centre is in the
medulla
drugs that decrease motility in the gut have mechanisms of actions that operate via
opiate receptors in the GI tract to decrease ACh
anti-spasmodics can be used to reduce symptoms due to…
IBS
renal colic
three mechanisms of anti-spasmodics
anti-cholingeric muscarinic antagonists
direct smooth muscle relaxants
calcium-channel blockers
4 types of laxative
bulk
osmotic
stimulant
softeners
Aminosalicylates
anti-inflammatory effects
corticosteriods
anti-inflammatory effects
biologics (anti-TNFalpa antibodies)
prevents action of TNFalpha (which is a key cytokine in inflammatory response)
other biologics
certolizumab
adalimumab
natalizumab
golimumab
vedolizumab
drugs affecting biliary secretions act by
reducing bile salts by binding with them in the gut and then excreting as insoluble complex
GI or liver disease can affect the process of a drug (ADME)
absorption
distribution
metabolism
excretion
distribution can be hindered when there is…
low albumin (decreased binding)
metabolism of the drug can be hindered by
liver enzymes
increased gut bacteria
gut wall metabolism
ulcer causation and increased GI bleeding can be the result of what drugs?
aspirin
NSAIDs
warfarin
Type A adverse drug reaction can be
intrinsic hepatotoxicity
idiosyncratic hepatotoxicity is a what?
Type B adverse drug reaction
A common gastrointestinal adverse effect (from a drug) is
drug induced liver injury
risk factors for Adverse drug reactions
age
sex
alcohol
genetic factors
malnourishment
liver disease classification
child-pugh
drugs dangerous to liver
warfarin/anti-coagulants (clotting factors are already low in the liver)
aspirin/NSAIDs (can increase bleeding time)
opiates (increases sedation)
