abdominal Flashcards
gaviscon
antacid
how does gaviscon work
contain an alginate + antacids (sodium bicarb)
antacids buffer stomach acids
alignates increase viscocity of stomach contents = reduce reflux of stomach acid. react w gastric contents = floating raft = separate gastric content to prevent mucosal damage
indications for gavison/antacids
GORD -symptomatic relife of heart burn
dyspepsia (indigestion) - short term relife
contraindications for gaviscon/antacids
sodium and potassium containing prepatons as can cause fluid overload or hyperkalaemia
ranitidine
H2 antagonist
H2 antagonist mode of action
reduce gastric acid secretion
indications for H2 antagonist
peptic ulcer disease
GORD and dyspepsia for releif of symptoms
alternative for h2 antagnosit
PPI
contraindications for H2 antagonist
renal impairment - since they are excreted by kidneys
distguise symptoms of gastric cancer
side effects of H2 anatagonsit
few
bowel distrubance, headahce, dizzines
omeprazole
PPI
PPI mode of action
reduce gastric acid secretion, act by irreversibly inhibiting H+/K+ - ATPase in gatric parietal cells
suppress gastric acid secretion almost completely, unlike H2 antagonist
indications for PPIs
preventation and treatment of peptic ulcer disease (inc NSAID caused)
symptomatic releif of dyspepsia and GORD
eradication of hpylori (+antibiotics)
contraindications of PPIs
disguise gastric cancer
elderly can increase risk of fractures
side effects of PPI
GI disturbances
headaches
increased risk of C diff
hypomagnesaemia
possible interactions of PPIs
reduces antiplatelet effect of clopidogrel by decreasing activation by cytochrome P450 enzymes
loperamide
antidiarrhoeal/antimotility drug
mode of action of loperamide
agonist of opioid receptors in GI tract - reduces peristaltic contractions in gut
= transit of bwoel contents is slwoed and anal sphincter tone is increased = more time for water absorption and stool hardening
inidcations for loperamide
symptomatic treatment for diarrhoea
in context of IBS and viral gastroenteritis
contraindcations of loperamide
avoid in acute UC where peristalissi s may increase risk of megacolon and perforation
not used in acute blood diarrhoea (dysentry) due to possible bacterial infection
dysentry
acute blood dirrhoea
side effects of loperamide
few side effects
constipation, abdo cramping, flatulence
senna
stimulant laxative
mode of action of senna
stimulant laxatives increase water and electrolye secretion from colonic mucosa = increase vol of colonic content and stimulating perstalsis
indications of senna
constipation
as suppositories for faecal imopaction
contraindications for senna
stimulant laxatives not used in patients whom intestinal obstruction is suspected = insduce perforation
rectal preparations sually avoided if haemorrhoids or anal fissure present
side effects of senna
abdo pain or crmaping and diarrhoea
prolonged use = melanosis coli (reversible pigmentation of intestinal wal
mesalazine
all other variants end with salazine
aminosalicylates 5ASA
mode of action of mesalazine/ 5ASA
not fully understood
possbily reduce release of cytokines from gut mucosa
but reduece inflammation
indications fro mesalazine
prevent remission of UC
treat flare ups of UC
some forms of arthritis
crohns, but not so useful
contraindications for mesalzine
renal function monitored after 3 months and 1 ear
avoid in severe liver or renal impairment
side effects of mesalazine
diarrhoea, nausea, vomtiing, exacerbation of colitis symptoms, headache, hpersensitivity
metcloperamide
antiemetics
= dopamine D2 receptor antagonist
mode of action of antiemetics
block D2 receptors = prokinetic effect, promiting gastric emptying
effective in nausea and vomititng due to CTZ stimulation and reduced gut moility (due to opioids or diagbetic gastroparesiss)
indications of antimetics
prophylaxis of nausea and vomtiing
contraindications of antiemetics
avoid in children and young adults
not in paitents with GI obstruction and perforation
side effects of antiemetics
risk of extrapyramidal side effects increased when prescribed with antipsychotics
should not be prescribed with dopaminergic agents for parkinsosn as will antagonise effects
