A paramedic is ordered to administer 450 mg of calcium chloride. The medication is supplied as 1 g in 10 mL. How many milliliters should be drawn up?

A paramedic is ordered to administer 450 mg of calcium chloride. The medication is supplied as 1 g in 10 mL. How many milliliters should be drawn up?

• A. 0.45 mL
• B. 0.045 mL
• C. 4.5 mL
• D. 5 mL

Answer: (C)

Concentration-based dosing: convert the supplied solution to mg per milliliter, then use that to find the volume for the desired dose. The preparation is 1 g in 10 mL, which is 1000 mg per 10 mL, or 100 mg per mL. To obtain 450 mg, you need 450 mg ÷ (100 mg/mL) = 4.5 mL. Draw up 4.5 mL to deliver the correct 450 mg dose.

Concentration-based dosing: convert the supplied solution to mg per milliliter, then use that to find the volume for the desired dose. The preparation is 1 g in 10 mL, which is 1000 mg per 10 mL, or 100 mg per mL. To obtain 450 mg, you need 450 mg ÷ (100 mg/mL) = 4.5 mL. Draw up 4.5 mL to deliver the correct 450 mg dose.