A client receives a prescription for hydromorphone 1 mg IV every 2 to 3 hours PRN for pain. The medication is available in a 2 mg/mL vial. How many mL should the nurse administer? (Enter numerical value only.)

Calculation: Identify the desired dose: Desired dose = 1 mg Available concentration = 2 mg/mL Calculate the volume to administer: Volume to administer (mL) = Desired dose (mg) / Available concentration (mg/mL) = 1 mg / 2 mg/mL = 0.5 mL