Questions

Each question carries 20 marks.

1. A 56-year-old Chinese woman presented with tea-colored urine, malaise and loss of appetite for 2 weeks. She does not drink alcohol. The diagnosis of acute exacerbation of chronic viral hepatitis B infection was supported by the presence of HBV ("hepatitis B virus") surface antigen and e antigen. Other investigation results revealed total bilirubin 16 μmol/L, ALT ("alanine transaminase") 460 IU/L, and HBV DNA level > 20000 IU/mL. The ultrasound scan of liver revealed no evidence of liver cirrhosis. The treating physician is considering antiviral agents for treatment of HBeAg ("hepatitis B e-antigen") positive chronic HBV infection. She also had a past medical history of seizures, diabetes mellitus, hypertension, supraventricular tachycardia, hyperlipidaemia, and GERD (“gastroesophageal reflux disease”). Her medications included phenytoin, metformin, lisinopril, verapamil, simvastatin, and lansoprazole.

(a) Discuss the PROS and CONS of various antiviral treatment options for the patient: Entecavir (“ETV”), Tenofovir disoproxil fumarate (“TDF”), Tenofovir alafenamide (“TAF”) and Peginterferon (“PEG-INF”). (8 marks)

(b) Describe the pharmacokinetic changes in severe liver cirrhosis (Child- Pugh Class C) and the impact on phenytoin metabolism. (3 marks)

(c) As her liver disease progresses to the stage of severe cirrhosis (decompensated), how would you advise to adjust her medications for treatment of diabetes mellitus, hypertension and supraventricular tachycardia, hyperlipidaemia and GERD, and explain the reasons for changes? (9 marks)

2. A 35-year old lady suffers from recurrent attacks of migraine. She experiences severe headaches with associated visual auras 5 days a month. Over-the-counter analgesics were ineffective. Her migraines are more frequent when she has her menses.

(a) Describe the mechanism of action of non-steroidal anti-inflammatory drugs in acute migraine. (3 marks)

(b) Explain the mechanism of action of triptans in the treatment of acute migraine. What are the contraindications? (4 marks)

(d) Describe FOUR classes of drugs that may be used first line for migraine prophylaxis. What are the common side effects for each of these medications? (4 marks)

(e) What is "medication overuse headache"? How is this defined? (3 marks)

(f) How should medication overuse headache be managed? (3 marks)

3. Mrs Lee is 65 years old and retired. She loves internet surfing and eating. She feels fatigue and increased thirsty recently thus having a body check-up.

Her body mass index ("BMI") is 30.3.
Her blood test and oral glucose tolerance test ("OGTT") results are shown below:
HbA1c ("glycated haemoglobin"): 7.2 %
Fasting plasma glucose: 7.4 mmol/L
Total cholesterol: 245 mg/L
Plasma triglyceride: 205 mg/L
OGTT: 11.3 mmol/L

(a) What type of disorder does Mrs Lee likely have? Explain your answer. (4 marks)

(b) What is the most commonly prescribed first line drug for the management of Mrs Lee's disorder? What is the mode of action of this first-line drug? (3 marks)

(c) Name THREE other classes of medications that can also be used with the first-line drug to manage Mrs Lee's disorder. Describe the mode of actions and side effects of the THREE medications in different classes. (12 marks)

(d) In addition to medication, could you provide TWO non-pharmacological advice to Mrs Lee for the management of her disorder? (1 mark)

4. A 78-year-old male smoker with severe chronic obstructive pulmonary disease ("COPD”) (FEV1 48% predicted) was admitted to Accident & Emergency ("A & E") department for the fourth time within 12 months. He presented to A & E with high fever (39.5°C), increased productive cough with expectoration of yellow sputum and shortness of breath. Upon admission, chest X-ray showed lung consolidation. From his previous medical record, the doctor noticed the detection of Pseudomonas aeruginosa in his prior admission. Both ciprofloxacin and gentamicin with good antipseudomonal activity have been used in this patient.

(a) Which classes of antibiotics do ciprofloxacin and gentamicin belong to? (2 marks)

(b) Describe the mechanisms of action for ciprofloxacin and gentamicin. (6 marks)

(d) Name TWO mechanisms of resistance which may develop with ciprofloxacin and gentamicin respectively. (4 marks)

(e) State FOUR reasons for the increase in prevalence of antibiotic resistance over the years. (4 marks)

5. Mary is a healthy 12-year old girl who recently started 1st year of secondary school. Her teacher reports that she often daydreams in class. Parents also report that completing her homework is a daily struggle and she does not do well in school examinations.

She was referred to the paediatric neurology service for assessment, her EEG ("electroencephalography") was normal and no other abnormality was found physically. Mary was then referred to paediatric services for further assessment. She was subsequently diagnosed with attention-deficit/hyperactivity disorder (“ADHD”).

(a) Why was she given EEG at the neurology clinic? (2 marks)

(b) Mary does not have any symptoms of hyperactivity. What other examples of attention deficit symptoms are frequently experienced by children with ADHD? (2 marks)

Parents are not keen for Mary to start stimulants and prefer non-stimulant treatment.

(c) What is the first-line stimulant treatment in Hong Kong and what are the pharmacological actions of stimulants? (3 marks)

(d) What pharmacological treatment would you recommend? Explain the pharmacology, pharmacokinetic profile, efficacy and safety profile as requested by her parents so that they can discuss this further with the paediatric team. (13 marks)

END OF PAPER

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