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Flashcards in Drugs and Liver disease Deck (37)
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1
Q

what affect does alcohol have on MI mortality?

A

halves it

2
Q

what are 4 causes of liver disease?

A

diet/obesity
alcohol
HCV or HBV
Drugs

3
Q

how is degree of liver disease established?

A

child pugh classification
score of 5-6 = Grade A
7-9 = grade B
10-15 = grade C

4
Q

what is cirrhosis?

A

liver gets encapsulated in fibrous capsules

small and shrunken liver

5
Q

what are 3 major factors in cirrhosis?

A

reduced liver blood flow (causes portal hypertension)
reduced metabolic function
reduced plasma proteins

6
Q

what painkiller should be used if the patient has cirrhosis?

A

not NSAIDs as switches off renal prostaglandins
not opiate
not paracetamol
lesser of all evils = small dose of paracetamol short term

7
Q

why is the shunting of blood in portal hypertension significant?

A

blood by-passes liver so does not get filtered and cleaned

drugs, toxins etc can go through circulation and reach brain etc

8
Q

what contributes of ascites?

A

high portal pressure and low albumin

9
Q

name some highly metabolised drugs, what impact does this have?

A

GTN, calcium blockers, phenytoin

don’t work well if swallowed as immediately metabolised so given enterally etc so they last longer

10
Q

what clue indicates that a drug is very highly metabolised?

A

if the oral dose is much higher than IV dose

11
Q

which order is alcohol metabolised?

A

first order until a point then zero order
i.e - drinking slowly every hour alcohol is metabolised at same rate as ingestion, if drinking quicker it isn’t metabolised as quickly

12
Q

what does low albumin do to circulation?

A

low albumin causes baroreceptors to perceive plasma volume as low activating RAAS producing more aldosterone

13
Q

Why is aldosterone so high in cirrhosis?

A

People with aldosterone cant metabolise aldosterone causing secondary aldosteronism

14
Q

what causes spider naevi?

A

increases oestrogen as cirrhotic liver cant metabolise oestrogen (in men and women)

15
Q

what are the consequences of cirrhosis on the kidney?

A

angiotensin 2 and aldosterone, sympathetic activity and ADH act on kidney causing constriction
results in sodium retention and potassium loss

16
Q

what causes sodium retention in cirrhosis?

A

vasopressin

17
Q

what reverses the actions of cirrhosis on the kidney?

A

spironolactone
fluid restriction
regular weight check to see what fluid has been lost

18
Q

why does alcohol intake not cause bad effects in normal people?

A

the same substances which act on the liver also stimulate it to produce renal prostaglandins which dilate the kidney

19
Q

what are some possible consequences of cirrhosis?

A
gut oedema (poor absorption)
swollen kidneys
liver and kidney congestion
gross oedema and ascites
CHF
20
Q

what are the negative results of NSAID’s?

A

reduce renal prostaglandins

increase peptic ulcers (risk of bleed etc)

21
Q

what is long term aspirin (COX 2/1? inhibitor) always prescribed with?

A

PPI

22
Q

what is the prescription cascade?

A

using drugs to counteract the side effects of other drugs in a cascade

23
Q

what is the prescription cascade?

A

using drugs to counteract the side effects of other drugs in a cascade

24
Q

which phase do drugs for liver disease affect?

A

phase 2

25
Q

which drugs have a reduced metabolism?

A
opiates (eg. codeine)
Benzodiazepines
Chlormethiazole
Cyclosporin
Metronidazole
Calcium blockers
26
Q

how does paracetamol toxicity occur?

A

8% is metabolised into N- acetyl - p - benzoquinonimime (via P450) which is highly reactive and dangerous
.

27
Q

why is paracetamol not as dangerous if youre drunk?

A

alcohol sits on CYP2E1 so paracetamol cant be absorbed

28
Q

what counteracts paracetamol overdose?

A

glutathione

29
Q

is paracetamol more dangerous in alcoholics?

A

yes

they produce more P450 so more is converted to toxic N-acetly-p-benzoquinonimine

30
Q

what is the most common drug induced liver disease?

A

amoxicillin and clavaulonic acid

31
Q

what is Hy’s rule?

A

Describes risk of fatal drug induced liver disease

ALT/AST > 5 X ULN and bilirubin > 3

32
Q

which diuretic is best in liver disease?

A

spironolactone

33
Q

what are the worst hepatic disorders?

A

fulminant hepatitis

34
Q

which secretion pathway is best for liver disease drugs?

A

renal excretion

35
Q

what is the general rule for prescribing in liver disease?

A

start low, go slow

36
Q

what is phase 1 of drug metabolism?

A

biotransformation
P450
oxidation, reduction and hydrolysis
affected early by fat soluble drugs

37
Q

what is phase 2 of drug metabolism?

A

conjugation

affected late

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