A physician orders 10 mg of Compazine. You have 5 mg/mL on hand. How many milliliters will you administer?

A physician orders 10 mg of Compazine. You have 5 mg/mL on hand. How many milliliters will you administer?

• A. 1 ml
• B. 1.5 ml
• C. 2 ml
• D. 2.5 ml

Answer: (C)

To figure out how many milliliters to give, use Volume = Dose / Concentration. The order is 10 mg and the solution is 5 mg per milliliter, so 10 mg ÷ 5 mg/mL = 2 mL. Therefore, administer 2 milliliters to deliver the prescribed 10 mg. Each milliliter contains 5 mg, so 1 mL would be 5 mg, 1.5 mL would be 7.5 mg, and 2.5 mL would be 12.5 mg, illustrating why 2 mL matches the required dose.

To figure out how many milliliters to give, use Volume = Dose / Concentration. The order is 10 mg and the solution is 5 mg per milliliter, so 10 mg ÷ 5 mg/mL = 2 mL. Therefore, administer 2 milliliters to deliver the prescribed 10 mg. Each milliliter contains 5 mg, so 1 mL would be 5 mg, 1.5 mL would be 7.5 mg, and 2.5 mL would be 12.5 mg, illustrating why 2 mL matches the required dose.