PART II-ESSAY QUESTIONS 

1. Pharmaceutical Calculations 

a) How much water should be added to 30% w/v ammonia water to make 4 L of ammonia water 10.32% w/w (specific gravity = 0.96)? Specific gravity = density at room temperature = 0.96 g/mL 

(4 marks) 

b) You would like to prepare 30 mL of an isotonic solution containing 0.45% of drug X. How many mg of sodium chloride should be used to make this isotonic solution? (sodium chloride equivalent (E)-value of drug X = 0.18) 

(3 marks) 

c) You would like to prepare some Lidocaine suppositories (using Cocoa Butter as a base). The suppositories will be made using a 4 gram mould and each suppository will contain 10 mg Lidocaine. You need to supply 20 suppositories. Given that the displacement value of Lidocaine in Cocoa Butter is 0.5, calculate how much base and active ingredient are required if a surplus of 2 suppositories are to be made. 

(3 marks) 

d) Patient DJT is a 77-year-old, 230-pounds, 6 ft 2 male. He is presenting with symptoms of acute ischemic stroke and requires fibrinolytic treatment. The recommended treatment dose of alteplase ("tPA") for acute ischemic stroke is 0.9 mg/kg (not to exceed 90 mg total treatment dose) infused over 60 minutes with 10% of the total treatment dose administered as an initial bolus over 1 minute. The doctor ordered the standard dosing above and you are requested to prepare the medication. 

(i) The reconstituted solution contains 100 mg tPA in 100 mL. How much volume do you discard from the bottle? 

(ii) From the remaining infusion solution, you first draw up the initial bolus dose. What is the dose of the initial bolus dose? 

(iii) The remaining solution is for infusion. What is the appropriate infusion rate, in mL/h? 

(3 marks) 

e) Subsequently, patient DJT from part (d) presents with cerebral edema so HYPERTONIC saline (sodium chloride 3% solution) intravenous infusion is prescribed. You have CONCENTRATED sodium chloride ("NaCl") 23.4% (w/v) solution (30 mL/vial) for injection and normal saline (sodium chloride 0.9% for injection). Molecular weight of NaCl is 58.44 g/mol. 

(i) You are asked to prepare a 250 mL bag of HYPERTONIC saline for infusion, by diluting the CONCENTRATED NaCl solution with normal saline. For the bag, how much CONCENTRATED NaCl solution and normal saline is required respectively, in mL? 

(ii) What is the approximate osmolarity of the HYPERTONIC 3% NaCl solution, in mOsmol/L? 

(2 marks) 

f) When receiving the hypertonic saline in part (e), patient DJT is found to be in septic shock, and therefore multiple antibiotics, including vancomycin, are started. 

(i) DJT's serum creatinine is 80 umol/L today. What is his estimated creatinine clearance ("CrCL"), in mL/min? 

(ii) Your hospital protocol provides formulae for estimating patient's vancomycin clearance ("CL") and volume of distribution ("Vd") as follows: 

Vd (L) = 0.72* Weight (kg) using total body weight 

CL (mL/min)= 0.689*CrCL (mL/min) + 3.66 

What is the expected half-life of vancomycin in DJT? 

(iii) The doctor prescribed vancomycin 1000 mg IV Q12H. What is the expected area-under-the-curve ("AUC") and steady state trough concentration? 

(3 marks) 

g) Eventually DJT's conditions deteriorate and have to be put on palliative care. 

(i) DJT complained of excruciating pain. After a few days of poor pain control despite aggressive analgesia, anesthesiologist is consulted and patient controlled analgesia ("PCA") is initiated in DJT with the following settings: 

• Drug: Morphine 5 mg/mL solution
• Demand dose (bolus dose): 2 mg 
• Basal rate: 4 mg/h 
• Lockout time (delay): 10 minutes 
• Hourly limit (including basal infusion): 12 mg 

In the past 12 hours, it is recorded that DJT pressed the button at the these times: 

00:02, 03:35, 06:44, 07:32, 08:03, 08:15, 08:25, 08:40, 08:51, 09:04, 09:32, 09:54, 10:11, 10:13, 10:15, 10:18, 10:22, 10:34, 11:13, 11:45 

How much morphine did DJT receive in the past 12 hours? 

(ii) DJT insists to be discharged home. Therefore, doctor prescribes the following discharge medication, together with a long-acting opioid analgesic, for his severe pain: 

Morphine 15mg PO Q2H PRN Pain x 10 days (Dispense 50%) 

Your pharmacy stocks morphine 10 mg and 30 mg prolonged release tablets, and morphine 50 mg/5 mL syrup in 120 mL bottles. What quantity would you dispense? 

(2 marks) 

2. Mrs. Brown was diagnosed with colon cancer with bone metastases and she is undergoing palliative care in a hospice. Mrs. Brown suffers from chronic cancer pain, and her medical officer decided to discharge her for palliative care at home. Recently, she has been converted from Morphine sulphate subcutaneous ("SC") infusion to the outpatient prescription of Morphine sulphate sustained release ("SR") tablet 30 mg PO Q12H. 

a) List TWO advantages of administering opioid analgesics via SC infusion. (2 marks) 

b) Mrs. Brown complained of increasing chronic cancer pain after one month. 

(i) Calculate the required dose of Morphine PO for the management of her breakthrough pain. (1 mark) 

(ii) Recommend a dosage regimen of Morphine PO (including dosage form, dose, frequency and any additional instructions) for managing her breakthrough pain. (4 marks)

c) Describe the term "coanalgesic" in cancer pain management. List TWO categories of coanalgesics and ONE example of drug in EACH category. (3 marks) 

d) Mrs. Brown's renal function progressively worsened with eGFR ~55 mL/min/1.73 m2. Suggest at least TWO preferred opioids which are options for potential use in Mrs. Brown. (2 marks) 

e) Medical officer decided to prescribe Fentanyl transdermal patch for Mrs. Brown who is already opioid tolerant for compliance reason. 

(i) Based on her total daily dose of Morphine SR PO (i.e. 60mg/day), what is the suggested dose conversion to Fentanyl transdermal patch? (1 mark)

(ii) Specify the dosage regimen of Fentanyl transdermal patch (including dosage and frequency) you would recommend to her medical officer. (2 marks) 

3. Suppositories are a dosage form designed to deliver drugs through rectal and vaginal routes of administration. They have classically been cylindrical in geometry, longer than wide, with the most common shape being the 'bullet' or 'torpedo' shape. 

a) List THREE commonly used excipients in the suppository dosage forms. (3 marks) 

b) Depending on excipients, suppositories can be classified as lipophilic based or hydrophilic based. Please comment on their characteristics in terms of the incorporated drugs and the drug-release mechanisms. (6 marks) 

c) Suppositories have demonstrated the ability to systemically deliver pain relief and are sometimes used as an alternative to oral administration. Please provide justification for such use. (4 marks) 

d) Why are suppositories for systemic delivery recommended to apply at the lower part of the rectum? (2 marks) 

4. Mr. AB is a 78-year-old man living in residential care facility. He was admitted to hospital with aspiration pneumonia not improved on oral antibiotics. His past medical history includes Parkinson Disease, cerebral vascular accident ("CVA"), hyperlipidaemia, hypertension and ulcerative colitis. Medications on admission are: 

• Aspirin EC 100 mg po daily
• Pantoprazole 40 mg po daily
• Simvastatin 10 mg po daily 
• Diltiazem SR 180 mg po daily 
• Levodopa / Carbidopa CR 100 mg / 25 mg po QID 
• Azathioprine 50 mg po daily 
• Amoxycillin 875 mg / clavulanic acid 125mg po BD (day 7 of treatment) 

a) Mr. AB has been assessed as high aspiration risk, thicken diet and crushed medications have been prescribed. The medical team asked for your advice on the administration of this patient's medications. Perform a full medication review and give your advice on the medication administration of this patient. Provide rationale for your recommendations which may include alternative treatment options. (7 marks) 

b) What parameters should be monitored in Mr. AB to ensure the efficiency and safety of the treatment regimen you suggested in part (a)? (4 marks) 

c) Apart from the infection issue, suggest how you will optimise the pharmaceutical care of this patient. Identify TWO drug related problems and give recommendations accordingly. (4 marks) 

5. WWC is a 68-year-old male admitted for hyperglycaemia (blood glucose of 26.2 mmol/L) and dehydration. WWC complained of generalised malaise, extreme fatigue, and poor oral intake. He experienced dysuria and lower abdominal pain a week ago, and was given some antibiotics. His past medical history include type 2 diabetes, hypertension, and dyslipidaemia. 

Some of WWC's home medications include glimepiride, metformin, lisinopril, simvastatin, and diltiazem. Upon laboratory work-up, the results show an elevated serum creatinine (290 umol/L), potassium (5.2 mmol/L), and WBC (17.1 x109/L). 

a) Please identify WWC's admission condition, the likely cause of it, and state the recommended initial management for him. (6 marks) 

b) What are some of the pharmacological interventions that can be performed to optimise WCC's care in the hospital? (3 marks) 

c) Three days later, WWC's urine culture returned positive for Escherichia coli. He is still showing elevated WBC and body temperature despite ongoing treatment of IV ciprofloxacin. Please outline your assessment of the initial antibiotic choice. (3 marks) 

d) Two days later, sensitivity results showed E. Coli resistant to ciprofloxacin. What would be your current recommendation for the treatment of WCC's urinary tract infection (“UTI”) now? (3 marks) 

END OF PAPER