A nurse is preparing to administer phenytoin 200 mg PO to a client. Available is phenytoin oral suspension 125 mg/5 mL. How many mL should the nurse administer? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)

Calculation: Desired dose = 200 mg. Available concentration = 125 mg / 5 mL. Calculate the volume to administer. Volume (mL) = Desired dose (mg) / Available concentration (mg/mL) = 200 mg / (125 mg / 5 mL) = (200 × 5) / 125 mL = 1000 / 125 mL = 8 mL. Rounded to the nearest whole number: 8.