Prescribing in Liver Disease Flashcards
Name some causes of abnormal liver tests
Obesity Alcohol Drugs Fatty foods Fizzy drinks
What is cirrhosis?
Cirrhosis is scarring of the liver as a result of continuous, long-term liver damage. Scar tissue replaces healthy tissue in the liver and prevents the liver from working properly.
Name 3 major factors contributing to cirrhosis?
Reduced liver blood flow as it is hard for the blood to get through from the portal system
Reduced metabolic function
Reduced plasma proteins
Describe a standard case of cirrhosis
Middle aged man, alcoholic, complaining of severe chest pain due to many fractured ribs from falling over drunk
Increased creatinine, decreased Na and K+
Low blood pressure
How can we treat cirrhosis?
NSAID
Paracetamol
Opiate
What is a clue of first pass metabolism
Oral dose is greater than the IV dose
What type of blood does not go through the liver?
Blood that is shunted
What is the result of 70-90% metabolism
Increased plasma levels
What has to happen to pro drugs to become active? Give an example of a pro drug
They need to be metabolised first
Codeine
What happens to the plasma volume if albumin is low
The plasma level is low
What is aldosterone?
A steroid with a complex structure
No steroid is well metabolised in the liver
What do patients with aldosteronism require and why
IV vitamins all the time to prevent brain damage
What happens to the plasma concentration of hormones
It increases as the liver cannot metabolise them very well
Why can male alcoholics get female characteristics?
Because they dont metabolise oestrogen so it builds up in their body
What happens to a patient with hepato-renal syndrome>
It is very hard to reverse and there is a high mortality rate as the kidney is basically falling apart
What type of drugs can induce renal failure?
NSAID as they get rid of protoglandins
describe 3 signs of moderate hepatic impairment
Decrease renal clearance
effect on unbound drug masked by decrease protein binding
renal function reduced
describe 3 consequences of moderate hepatic impairment
Gut oedema
Liver and kidney congestion
Gross oedema and ascites
CHF
Name 8 adverse affects of NSAIDs
UGI ulcer complications CV toxicity Hypertension CHF Sodium Retention Asthma Diarrhoea / Colitis Renal Failure
What should always be co-prescribed with a proton pump inhibitor (PPI)
NSAID or COX2 inhibitor
Describe the prescribing cascade
One drug that is prescribed may give unwanted side effects which have to be treated with another drug. This is not cost effective
Why might the diaphragm not be able to be pushed down in breathing?
Ascities - fluid blocks it
What are the phases of drug metabolism
Phase 1 (early) and phase 2 (late)
What drugs are are best for treating early stages of lvier disease?
Phase 2 metabolised drugs so that they will be properly metabolised
Name some drugs which have reduced metabolism
Opiates (codeine) Benzodiazepines Chlormethiazole Cyclosporin Metronidazole Calcium blockers
How long does it take for symptoms of a paracetamol overdose to appear?
Around 4 days
What does alcohol do to the receptors
It blocks the receptors if it is on board which is good
What happens for chronic alcoholics and paracteramol
It gets metabolised faster which is worse for the patient
Name 4 effects of Paracetamol in liver disease
reduced glutathione stores
longer half-life
increased P450 in acloholics
Toxicity with normal doses
Name 2 other drugs which cause liver disease
Flucloxiclav and Amoxicillin
Is drug induced liver injury more common in men or women
Women
What is the best diuretic to give in liver disease?
Spironolactone
What are the requirements for patients to be on spironolactone?
Fluid restriction (1L) Use at high doses 1kg/day weight loss (aim)
Are antibiotics safe to give in liver disease?
Yes
What are the worst hepatic disorders?
Fulminant hepatic failure
Decompensated cirrhosis
severe acute or chronic hepatitis
severe congestive heart failure
What is the main message of drugs and liver disease
Dose reduction regardless of the route of elimination of drug or metabolite
Name some general principles in presribing in liver disease
Avoid pro drugs Use drugs with renal excretion Be wary of sedatives, CNS drugs, anticoagulants, NSAIDs, theophyllines, aminoglycosides high inter-inividual variability Liver tests not predictive Start low, go slow