A nurse is preparing to administer phenytoin 75 mg PO. Available is phenytoin suspension 25 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.)

Step 1: Determine how many milligrams are in each milliliter of the suspension. Total milligrams ÷ Total milliliters 25 mg ÷ 5 mL = 5 mg/mL Step 2: Determine how many milliliters are needed to administer 75 mg. Desired milligrams ÷ Milligrams per milliliter 75 mg ÷ 5 mg/mL = 15 mL