Questions
a) A physician writes the following medication order for a 3 year old girl (weight 35 lbs) admitted to the hospital:
Propranolol 0.17 mg/kg/dose Q8H x 1 day
Propranolol 0.33 mg/kg/dose Q8H x 1 day
Propranolol 0.67 mg/kg/dose Q8H x 3 days
The pharmacy has the following recipe for compounding propranolol as an oral suspension. The suspension may be stored in the refrigerator for up to 45 days.
i) How much (in ml) of the above suspension would you inform the nurse to administer to the patient per dose during the first three days. (3 marks)
ii) A week after admission the patient is discharged with a prescription for propranolol 0.67 mg/kg/dose Q8H for 20 days. How much of each ingredient would you need to prepare a sufficient amount to dispense? (3 marks)
b) A 6 month old infant (weight 7.8 kg) is admitted to the paediatric intensive care unit due to signs of severe dehydration. The physicians write the following medication orders for the patient:
-IV fluids (1/2 NS + D5W) 650 ml
-Potassium: 1.4 mmol/kg/day
i) How much (in mL) of a 14.9% KCl solution would the patient need for day? (KCl = 74.5) 2 marks
ii) What is the osmolarity (mOsmol/L) of the above IV solution (with KCl added?) (NaCl=58.4; D5W = 180) 3 marks
c) A 73 year-old male (weight 68 kg) is admitted due to severe pneumonia. Shortly after admission he goes into septic shock and is prescribed dopamine 5 mcg/kg/min. You pharmacy stocks 400 mg in 250 ml premixed solution. At what rate (mL/min) would you instruct the nurse to administer the prepared solution? 2 marks
d) A prescription calls for 800 mL of 5% sodium bicarbonate solution. You have the following concentrations of sodium bicarbonate in stock: 500 mg/15 ml and 1500 mg/15 ml. How much of each would you need to prepare th above prescription? 2 marks
e) A patient (weight 45 kg) received vancomycin 1000mg IV Q 12h. The drug was infused over 60 minutes. Trough concentrations measured after the 1st dose was 28 mcg/ml (Vd = 0.5 L/kg)
i) What is the half life of elimination of the drug? 3 marks
ii) How long would it take for to reach serum levels of 18 mcg/mL after the above measured trough level? 2 marks