A client with multiple sclerosis (MS) is receiving interferon beta-Ib 0.1875 mg subcutaneously every other day. The nurse reconstitutes the vial by slowly injecting 2 mL of diluent into the interferon vial for a reconstituted solution of 0.25 mg/1 mL. How many mL should the nurse administer? (Enter numeric value only. If rounding is required, round to the nearest hundredth.)

To determine the correct dosage, the nurse should use the concentration of the reconstituted solution which is 0.25 mg per 1 mL. Since the prescribed dose is 0.1875 mg, the nurse needs to calculate the volume of the reconstituted solution that contains this dose. By dividing the prescribed dose (0.1875 mg) by the concentration of the solution (0.25 mg/mL), the result is the volume to administer. Therefore, the nurse should administer 0.75 mL of the reconstituted solution.