RACP-Pharm

Question 1

A 40-year-old Ethiopian lady is admitted with pneumonia and pleuritic chest pain. She is commenced on Paracetamol 1g QID and Codeine 60 mg QID. The next day she is found to be drowsy and her respiratory rate is 8. You suspect that she is narcotised, and you administer Naloxone to which she responds well.
What is the cause of her presentation?
a) She is a fast CYP metaboliser
b) Accidental administration of Morphine
c) Accidental administration of higher doses of Codeine
d) Concurrent use of Paracetamol
e) Covert use of Endone

Answer 1

A- She is a fast CYP metaboliser

• Codeine is a prodrug that is metabolized by the CYP2D6 enzyme into morphine, which is responsible for its analgesic effects.
• Individuals with ultrarapid CYP2D6 metabolism convert codeine to morphine at a much higher rate, leading to elevated morphine levels and increased risk of opioid toxicity (e.g., respiratory depression)

Question 2

Which is the following if co-administered with Dabigatran will likely to lead to a rise in the serum concentrations of Dabigatran?
a) Itraconazole
b) Adenosine
c) Verapamil
d) Metoprolol
e) Paroxetine

Answer 2

A) Itraconazole

Dabigatran is a substrate of p-glycoprotein

both itraconazole and verapamil are inhibitors which would therefore result in an increase in the serum concentration of dabigatran

itraconazole more than verapamil

Question 3

Which of following medications decreases the effect of Tamoxifen in hormone positive Breast Cancer?
a) Paroxetine
b) Warfarin
c) Verapamil
d) Carbamazepine
e) Alcohol

Answer 3

A) paroxetine

Question 4

When given orally what is the comparative dose of prednisone to hydrocortisone 100mg?

A) 4mg
B) 10mg
C) 25mg
D) 40mg
E) 100mg

Answer 4

answer: C
4 dexamethasone, 25mg prednisone, 100 hydrocortisone

Question 5

Which drug is most likely to cause rebound hypertension when stopped abruptly after chronic use?

A. Clonidine
B. Prazosin
C. Metoprolol
D. Hydralazine

Answer 5

A. Clonidine

Question 6

70. What is the half life of levothyroxine (thyroxine)?
    A) 1 day
    B) 7 days
    C) 21 days
    D) 42 days

Answer 6

B) 7 days

Question 7

76. An 80M with T2DM was commenced on Metformin by his GP. Which of the following vitmain is he at risk of becoming deficient of?
    A) B12
    B) B6
    C) Vit C
    D) Vitamin D

Answer 7

A) B12

B6 is pyridoxine

Question 8

What is the MOA of phenytoin?

Answer 8

blocks voltage-gated sodium channels, stabilizing neuronal membranes and reducing repetitive firing of action potentials.

Question 9

What is the MOA of phenobarbital?

Answer 9

Phenobarbital enhances GABAergic activity by increasing the duration of chloride channel opening at GABA-A receptors, leading to neuronal hyperpolarization and CNS depression.

Question 10

15. What is the most common side effect of osteltamivir?
    A) Hepatitis
    B) Rash
    C) Nausea and vomiting
    D) Confusion

Answer 10

C) Nausea and vomiting

Question 11

20. Which of the following synthetic disease modifying agents predisposes to the development of SCC of the skin?
    A) Azathiopurine
    B) Leflunomide
    C) Methotrexate
    D) Mycophenalate

Answer 11

A) Azathiopurine

Question 12

Q74. A 72 year old man has a history of AF and is known to be a fast CYP2D6 metaboliser with a history of
previous codeine toxicity. Which rate control agent will be expected to have an expected increased dose, given
the pharmacogenetics?
A. Amiodarone
B. Metoprolol
C. Digoxin
D. Verapamil

Answer 12

B. Metoprolol

Metoprolol is metabolized by CYP2D6. A fast metabolizer would require higher doses for therapeutic effect.