GI + HPB Flashcards
name some common drugs that undergo extensive FPM
aspirin levodopa lidocaine morphine propranalol salbutamol
name 3 ways in which liver impairment can affect drug metabolism
1) drug accumulation due to less metabolic activity
2) decreased active drug availability due to decreased active-metabolite
3) increase in free active drug due to hypoalbunaemia
phenytoin is not a hepatotoxic drug - T or F
F
it is safe to give anti TB drugs in liver failure - T or F
F
what is extraction ratio?
the % of drug in the blood that is removed each time it goes through the liver.
how does extraction ratio affect drug doses in liver failure
in oral medication
if high extraction ratio - must reduce both loading dose and maintenance dose
if low extraction ratio - reduce maintenance dose, but keep loading dose same
in IV medication
keep loading dose the same, but reduce maintenance dose
how to investigate suspected c diff
c diff stool test
flexi sig
management of C diff
14 days metronidazole, if not vancomycin
differentials diarrhea
gastroenteritis c diff pancreatitis alcoholic gastritis IBD ischaemic bowel
further investigations of diarrhea if suspecting cancer
flexi sig
faecal calprotectin
faecal elastase
CT abdomen
causes of secondary constipation
opiates, iron, CCB neurological damage dietary mechanical obstruction - cancer, stricture, painful anus metabolic endocrine
what are metabolic causes of constipation
high or low calcium
low potassium
low mg
2 endocrine causes of constipation
hypothyroidism
diabetes
when to investigate further in constipation
if over 40 years old or
iron def anaemia, associate red flag symptoms
4 types of laxatives
bulk forming - ispaghula husk
osmotic - macrogol
stimulant - senna
stool softeners - docusate
how to go about management constipation
1st line - ispaghula husk
2nd line - macrogol
if not then add stimulant
how to manage opioid induced constipation?
osmotic and stimulant laxative
what must patient be encouraged to do when given bulk forming laxative?
drink water
what is a common contraindication of laxatives
intestinal obstruction
what blatchford score is indicative of further investigation needed
> 0
what is dyspepsia
loose term describing symptoms of
epigastric pain (heartburn)
nausea, vomiting
bloating, fullness
what are some redflags in dyspepsia
weight loss upper GI bleed vomiting anorexia dysphagia haematemesis
causes of peptic ulcer disease
h pylori nsaid use stress long term steroid use smoking alcohol
symptoms of PUD
dyspepsia epigastric pain gastric bleeding weight loss anaemia
how can upper GI bleeding present
haematemesis
malaena
what 2 scoring systems used in pud/gastric bleeding
blatchford and rockall
differential diagnoses of PUD
ulcer pancreatitis gastric cancer reflux gall stones MI
how to manage PUD?
if under 55
test and treat - if clinical assessment suggests, do H pylori test, and if positive, treat
if over 55 - do endoscopy
how is h pylori tested for
urea breath test
stool antigen testing
HP antibody serum test
endoscopic biopsy tests
how is PUD managed if under 55, +veHP and on NSAIDs, incld monitoring
give 2 months of PPI first, then eradication therapy
7 days
PPI + amox + clarithro/metro
repeat endoscopy 6-8 weeks later
how is PUD managed if under 55, +ve HP, and not on NSAIDs, incld monitoring
eradication therapy, retest for HP after
how to manage if HP -ve?
4-8 weeks of PPI
what should be done if someone has PUD but needs to take NSAID?
give PPI also, consider switching to COX2 if low CDVS risk
how is alcohol metabolised in the liver?
ethanol —(ethanol dehydrogenase)–> acetyldehyde —(aldehyde dehydrogenase)—> acetic acid
what causes fatty acid accumulation in ALD?
increased ethanol metabolism causes depletion of NAD+ and increase in NADH, this causes decrease in fatty acid oxidation and increased hepatic fatty acid synthesis. fatty acids then esterified into glyceride
how does ALD cause damage to hepatocytes
increase in NADH causes necrosis of hepatic acinus, causing release of TNF-alpha and free radicals
what role does inflammation play in ALD
release of cytokines cause inflammation, neutrophil infiltration and cirrhosis
what are the stages of ALD
steatosis
alcohol steatohepatitis
alcohol cirrhosis
hepatic steatosis from alcohol is reversible - T or F
T, with abstinence
symptoms of ALD
can be asymptomatic, otherwise signs of liver damage incl. jaundice, RUQ pain, vomiting/nausea, hepatomegaly, ascites, fatigue, complications of cirrhosis
what are compliations of liver cirrhosis
jaundice, ascites, portal hypertension, bleeding varices, SBP, encephalopathy
biochemical marker picture in ALD
raised bili, ast, alt, alk phos, PT, low albumin
specific investigations in ALD
ultrasound
CT
biopsy
management of ALD
alcohol cessation - managed
thiamine
steroids
liver transplant
what is NAFLD associated with
metabolic syndrome
what is metabolic syndrome
hypertension insulin resistance central obesity hyperlipidaemia nafld
what is nafld
fatty liver causing inflammation, fibrosis and cirrhosis
what does nafld increase the risk of
cirrhosis, hcc, liver failure
what are symptoms of nafld
often asymptomatic, picked up incidentally
what are signs of nafld
abnormal lfts
hepatomegaly
ultrasound showing fatty liver
how is nafld diagnosed
raised alt/ggt
imaging evidence of steatosis
raised alt and evidence of metabolic syndrome
with no other possible causes of liver disease (alcohol, viral, autoimmune etc)
how is nalfd managed
lifestyle, exercise, diet, weight loss, alcohol cessation, treat metabolic syndrome
