The nurse plans to administer naloxone 1 mg. The label of the 10 mL vial indicates that the drug concentration is "Naloxone 0.4 mg/mL." How many mL should the nurse administer? (Enter numeric value only. If rounding is required, round to the nearest tenth.)

Identify the desired dose. Desired dose = 1 mg Identify the drug concentration on hand. Concentration on hand = 0.4 mg/mL Use the formula to calculate the volume to administer. Volume to administer (mL) = Desired dose (mg) / Concentration on hand (mg/mL) = 1 mg / 0.4 mg/mL = 2.5 mL