Pharmacy and PharmacologyDifficulty 3/5
A 44 lb dog is prescribed 2 mg/kg of a drug supplied at 50 mg/mL. What volume should be drawn?
- A0.4 mL, using half the calculated dose for safety
- B2.0 mL, rounding the dose up to the nearest whole millilitre
- C1.76 mL, using the dog's weight in pounds for the calculation
- D0.8 mL, after converting the weight to 20 kilograms
Show answer and rationale
Correct: D. 44 lb ÷ 2.2 = 20 kg. 20 kg × 2 mg/kg = 40 mg. 40 mg ÷ 50 mg/mL = 0.8 mL. Skipping the pound-to-kilogram conversion inflates the answer 2.2-fold.
- C — That result comes from using pounds directly as kilograms.
- A — Halving a prescribed dose is not the technician's decision.
- B — Rounding to a whole millilitre overdoses the patient by 150%.