A nurse is preparing to administer ceftriaxone 1 g IM every 12 hr. Available is ceftriaxone injection 450 mg/mL. How many mL should the nurse administer per dose? (Round the answer to the nearest tenth.)

Convert the ordered dose from grams to milligrams: 1 gram (g) = 1000 milligrams (mg) Ordered dose: 1 g = 1000 mg Determine the concentration of the ceftriaxone injection: Available concentration: 450 mg/mL Calculate the volume (in mL) to administer: Use the concentration as a conversion factor: Volume (mL) = Ordered dose (mg) / Concentration (mg/mL) Volume (mL) = 1000 mg / 450 mg/mL = 2.222 mL Round to the nearest tenth: 2.2 mL.