A medication order requires a 75 mg dose. If the medication is supplied as 50 mg/mL, how many milliliters are needed?

A medication order requires a 75 mg dose. If the medication is supplied as 50 mg/mL, how many milliliters are needed?

• A. 0.5 mL
• B. 1.0 mL
• C. 1.5 mL
• D. 2.0 mL

Answer: (C)

When you need to give a specific amount of medicine, use volume = dose / concentration. Here the prescribed dose is 75 mg and the solution is 50 mg per 1 mL, which is 50 mg/mL. So the volume required is 75 mg ÷ 50 mg/mL = 1.5 mL. The mg units cancel out, leaving mL as the volume to administer. For a quick check: 1 mL contains 50 mg, so 2 mL would be 100 mg; 1.5 mL gives 75 mg, which matches the order.

When you need to give a specific amount of medicine, use volume = dose / concentration. Here the prescribed dose is 75 mg and the solution is 50 mg per 1 mL, which is 50 mg/mL. So the volume required is 75 mg ÷ 50 mg/mL = 1.5 mL. The mg units cancel out, leaving mL as the volume to administer. For a quick check: 1 mL contains 50 mg, so 2 mL would be 100 mg; 1.5 mL gives 75 mg, which matches the order.