The nurse is preparing to administer a prescription for cefazolin 600 mg IM every six hours. The available vial is labeled, "Cefazolin 1 gram," and the instructions for reconstitution state, "For IM use add 2 mL sterile water for injection. Total volume after reconstitution equals 2.5 mL." When reconstituted, how many milligrams are in each mL of solution? (Enter numeric value only.

Calculation: Total cefazolin in the vial = 1 gram Convert the total amount of cefazolin from grams to milligrams: Total cefazolin (mg) = Total cefazolin (grams) x 1000 mg/gram = 1 gram x 1000 mg/gram = 1000 mg Identify the total volume after reconstitution: 2.5 mL Calculate the concentration of cefazolin in mg/mL: Concentration (mg/mL) = Total cefazolin (mg) / Total volume (mL) = 1000 mg / 2.5 mL = 400 mg/mL