A nurse is reconstituting a vial of powdered penicillin for IM injection. The label states to add 6.2 mL of sterile water to yield 500 mg/mL. The order is for 250 mg IM. How many mL should the nurse administer?

Identify the ordered dose and available concentration Ordered Dose: 250 mg Available Concentration: 500 mg/mL Calculate the volume to administer Volume to administer = Ordered Dose ÷ Concentration Volume to administer = 250 ÷ 500 = 0.5 mL