GI: Drugs and the Liver

Question 1

What is the usual option for cholelithiasis?

Answer 1

Surgery

Question 2

What can be used to resuce the itch in cholelithiasis?

Answer 2

ursodeoxycholic acid

Question 3

What is the pain relief treatment of biliary colic?

Answer 3

Analgesia - morphine, buprenorphine

Question 4

What relieves biliary spasm in biliary colic?

Answer 4

Atropine

GTN

Question 5

Why might morphine not be the best choice of pain relief in biliary colic?

Answer 5

Contricts the sphincter of oddi

Question 6

What happens to drugs that are metabolised in the liver?

Answer 6

Convert parent drugs to more polar metabolies that are not readily reabsorbed by renal tubules, facilitating excretion

Question 7

What can occasionally happen in liver metabolism?

Answer 7

Metabolites may gain activity (prodrugs)
Unchanged activity (diazepam)
Posses a different type of activity

Question 8

What are the two phases of liver drug metabolism?

Answer 8

Phase I= oxidation, reduction, hydrolysis- makes drug more polar
Phase 2= conjugation- adds an endogenous compound - more polar

Question 9

Give an example of drug metabolism.

Answer 9

Aspirin–>Salicylic Acid–>Glucuronide

Question 10

What happens to the metabolic function of the liver in cirrhosis?

Answer 10

Decreased

Decreased plasma proteins and blood flow

Question 11

Give examples of highly metabolised drugs

Answer 11

GTN
Phenytoin
Calcium channel blockers

Question 12

What substances build up and are not properly metabolised in liver cirrhosis

Answer 12

aldosterone
oestrogen
endothelin

Question 13

What happens if you give calcium channel blockers in cirrhotics?

Answer 13

Gut oedema
impaired renal and liver function
ascites
CHF

Question 14

What are the consequences of giving NSAIDs in cirrhotics

Answer 14

recreased renal prostaglandin= renal impairment and failure

increased peptic ulcer which is a bleeding risk

Question 15

How should you prescribe NSAIDs in cirrhotic

Answer 15

With a PPI

Question 16

Name drugs which have a reduced metabolism in the liver in cirrhotics

Answer 16

Opiates
Calcium channek blockers
benzodiazepines 
chloromethiazole
cyclosporin
metronidazole

Question 17

Why can paracetamol be toxic in the liver

Answer 17

It breaks down to a highly reactive intermediate called GLUTATHIONE
Becomes toxic at normal doses in liver cirrhotics

Question 18

How should paracetamol be prescribed in cirrhotics?

Answer 18

1g twice daily
No more than 3g
Codeine 30mg twice daily
AVOID NSAIDs

Question 19

What antibiotics can induce hepatitis

Answer 19

amoxicillin and clavulanic acid

Question 20

What is Hy’s Law?

Answer 20

If ALT/AST more than five times the upper limit of normal
and bilirubin more than 3
= risk of a drug causing liver injury

Question 21

What is the best diuretic to use in ascites in liver cirrhosis

Answer 21

spironolactone

Question 22

What antibiotics can be nephrotic

Answer 22

aminoglycoside eg gentamicin

Question 23

Which antibiotics can be epileptogenic

Answer 23

Quinolone

Question 24

What antibiotics have reduced metabolism in cirrhotics

Answer 24

metranidozole

Question 25

What class of drugs shoulf be avoided in cirrhotics

Answer 25

prodrugs

Question 26

What drugs should you be wary prescribing in liver cirrhotics

Answer 26

Sedatives
CNS drugs
Anticoagulants
NSAIDs
theophyllines
Aminoglycosides