Prescribing in Hepatic and Renal Impairment

Question 1

What does reduced liver function mean to drug bioavailability/dose

Answer 1

reduced dose and therefore therapeutic effect

important for narrow therapeutic drugs

Question 2

How does liver change as you age

Answer 2

reduced liver volume = liver impairment

Question 3

What does hypoproteinanaemia cause

Answer 3

reduced protein binding as less protein binding sites in body

Question 4

What does hypoproteinanaemia mean in terms of drugs and toxicity

Answer 4

it will increase level of free drug in blood, increasing toxicity

Question 5

What does vitamin k deficiency lead to

Answer 5

increased risk of bleeding

• give Menadiol (water soluble vitamin k) for vitamin k balance

Question 6

What are the fat soluble vitamins

Answer 6

ADEK

Question 7

What is Obstructive jaundice

Answer 7

blockage in bile ducks reducing or stopping bile flow from liver into small intestine

Question 8

What is the difference between intrahepatic and extrahepatic jaundice

Answer 8

Intra- blockage is inside the liver

Extra- blockage is outside the liver

Question 9

Why does obstructive jaundice affect fat soluble vitamin absorption

Answer 9

reduced bile into small intestine causes lowered emulsification and absorption of fat soluble vitamins

Question 10

Fusidic acid and obstructive jaundice

Answer 10

• impaired liver
• causes lowered excretion of fusidic acid from liver
• increased fusidic acid levels in blood
• causing toxicity
• impacting its effectiveness on biliary tract infections

Question 11

Rifampicin and obstructive jaundice

Answer 11

• impaired liver
• causes lowered excretion of rifampicin
• increasing its systemic levels
• can increase liver impairment

Question 12

What is hepatic encephalopathy

Answer 12

• liver detoxifies ammonia into urea normally
• impaired liver leads to build up of ammonia in blood
• it passes BBB and builds up in brain
• disrupting neurotransmission and brain function

Question 13

What is Grade I hepatic encephalopathy

Answer 13

Grade I: Subtle cognitive changes, euphoria or depression, mild confusion, and slight tremor.

Question 14

What is Grade II hepatic encephalopathy

Answer 14

Grade II: Increased drowsiness, lethargy, confusion, disorientation, and asterixis (flapping tremor).

Question 15

What is Grade III hepatic encephalopathy

Answer 15

Grade III: Stupor, marked confusion, severe disorientation, and incoherent speech.

Question 16

What is Grade IV hepatic encephalopathy

Answer 16

Grade IV: Coma, unresponsiveness to stimuli, and potential progression to death if untreated.

Question 17

What drugs can exacerbate hepatic encephalopathy

Answer 17

• Constipating drugs
  (opioids, TCAs)
• Sedating drugs
  (opioids, antihistamine, benzodiazepines)
• Hypokalaemic drug
  (Loop and thiazide like diuretics)

Question 18

How to treat hepatic encephalopathy

Answer 18

Lactulose

Question 19

What drugs can exacerbate Oedema and Ascities

Answer 19

drugs that cause fluid retention

(NSAIDs, Corticosteroids)

Question 20

Main hepatoxocic drugs

Answer 20

• Antipsychotics
• Amiodarone
• Carbamazepine
• Co-Amoxiclav
• Fluconazole
• Flucloxacilin
• Ketoconazole
• Labetalol
• Methotrexate
• Paracetamol
• Piolitazone
• Rifampicin
• Statins
• Valproate
• Tetracyclines

Question 21

What are the Signs of liver toxicity

Answer 21

• jaundice (yellow skin, eyes)
• abdominal pain
• nausea / vomiting
• weight loss
• dark urine
• drowsiness or confusion

Question 22

What does grapefruit do to cytochrome p450

Answer 22

enzyme inhibitor

Question 23

What does enzyme inhibition cause

Answer 23

increased plasma concentration

Question 24

What drugs will have increased plasma concentration with grapefruit

Answer 24

• CVS drugs
• CNS drugs
• Immunosuppressants
• Colchicine
• Sildenafil

Question 25

What CVS drugs interact with grapefruit juice

Answer 25

- amiodarone - statins - verapamil - CCB (amlodipine) - dihydropyrdine

Question 26

What CNS drugs interact with grapefruit juice

Answer 26

- Quetiapine - Sertraline

Question 27

What immunosuppressants drugs interact with grapefruit juice

Answer 27

- Tacrolimus - Ciclosporin

Question 28

What factors are HIGH in liver function test in liver impairment

Answer 28

- ALT - AST - ALP - GGT - Bilirubin - Prothrombin time / INR

Question 29

What factors are LOW in liver function test in liver impairment

Answer 29

Albumin

Question 30

When is ALT raised in a liver function test when there is liver impairment

Answer 30

raised transaminases in hepatocellular damage

Question 31

When are AST and ALP raised in a liver function test when there is liver impairment

Answer 31

raised in obstructive jaundice (found mainly in bile duct)

Question 32

What is bilirubin

Answer 32

it is a pigment in the bile that causes jandice

Question 33

Why is Albumin LOW in liver function test when there is liver impairment

Answer 33

because the liver can't make the protein as much in hepatic impairment

Question 34

What does reduced renal excretion of drugs cause

Answer 34

toxicity, as plasma concentration of the drug isn't excreted

Question 35

How should you handle the dose of a narrow therapeutic drug in renal impairment

Answer 35

close monitoring of plasma concentration and clinical response

Question 36

What does renal impairment do to plasma half life of drugs

Answer 36

increases it

Question 37

Why is renal impairment a problem in half life drugs

Answer 37

- some drugs require a loading dose before regular use - it will take longer to reach the drug steady state

Question 38

What are the signs of acute kidney injury

Answer 38

- reduced urine output - fluid retention - dehydration - nausea / vomiting - fatigue - High BP - confusion

Question 39

What will lab results show for acute kidney injury

Answer 39

- reduced eGFR - reduced creatinine clearance - high serum creatinine

Question 40

Examples of Nephrotoxic drugs

Answer 40

- ACE inhibitors - Aciclovir - NSAIDs -Tetracyclines - Quinolones - Aminoglycosides - Aminosalicylates - Cephalosporins

Question 41

What is the most significant risk factor or AKI

Answer 41

Dehydration

Question 42

What are renal impairment sick day rules

Answer 42

when unwell, stop taking certain medications

Question 43

When should you restart sick day rule medications

Answer 43

24-48 hours after eating and drinking normally

Question 44

What medications should you stop taking when feeling unwell with AKI (sick day rule medication)

Answer 44

- Diuretics - ACE Inhibitors - Metformin - NSAIDs

Question 45

Why should you stop taking Diuretics when feeling unwell with AKI

Answer 45

it exacerbates dehydration and electrolyte disturbances

Question 46

Why should you stop taking ACE Inhibitors when feeling unwell with AKI

Answer 46

they are nephrotoxic and they reduce eGFR

Question 47

Why should you stop taking Metformin when feeling unwell with AKI

Answer 47

increases risk of lactic acidosis in renal impairment

Question 48

Why should you stop taking NSAIDs when feeling unwell with AKI

Answer 48

they are nephrotoxic and they reduce eGFR, sodium and water retention

Question 49

Which equation do you use to calculate creatinine clearance

Answer 49

Cockcroft-Gault formula

Question 50

What is the Cockcroft-Gault formula

Answer 50

(140-age) X Weight KG X Constant ------------------------------------------------ Serum creatinine

Question 51

What is the Cockcroft-Gault formula constant for men and women

Answer 51

Men: 1.23 Women: 1.04

Question 52

If BMI is less than 18 what weight should be used in the Cockcroft-Gault formula

Answer 52

actual body weight

Question 53

if major contributor to high body weight is fat, what weight should be used in the Cockcroft-Gault formula

Answer 53

ideal body weight

Question 54

how to calculate ideal body weight

Answer 54

Constant + 0.91(height -152.4)

Question 55

What is the constant for men and women for the ideal body weight formula

Answer 55

Men: 50 Women: 45.5

Question 56

If eGFR is above 60 and the ACR is below 3 than what is the status of the kidney

Answer 56

Normal

Question 57

What is urine ACR

Answer 57

the ration between the amount of albumin to the amount of creatinine in the urine

Question 58

What drugs colour urine and bodily secretions RED

Answer 58

- Dantron - Doxorubicin - Levodopa

Question 59

What drugs colour urine and bodily secretions RED-ORANGE

Answer 59

- Rifampicin

Question 60

What drugs colour urine and bodily secretions ORANGE

Answer 60

- Sulfasalazine

Question 61

What drugs colour urine and bodily secretions YELLOW-BROWN

Answer 61

- Nitrofurantoin - Senna

Question 62

What drugs colour urine and bodily secretions PINK O ORANGE

Answer 62

- Phenindone

Question 63

What drugs colour urine and bodily secretions BLUE

Answer 63

- Triamterene

Question 64

What drugs colour urine and bodily secretions BLACK/TARRY

Answer 64

- Iron - Bismuth

Question 65

What drugs colour urine and bodily secretions BROWN

Answer 65

- Prostoglandin Analogues (latanoprost eye drops)