A nurse is preparing to administer phenobarbital 75 mg/kg PO to a client who weighs 178 lb. Available is phenobarbital 20 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: Convert the client's weight from pounds (lb) to kilograms (kg). Weight in kg = 178 lb / 2.2 lb/kg = 80.9090... kg Calculate the total desired dose in milligrams (mg). Desired dose = 1.75 mg/kg × 80.9090... kg = 141.5909... mg Determine the concentration of the available medication. Available concentration = 20 mg / 5 mL = 4 mg/mL Calculate the volume in milliliters (mL) to administer. Volume = Desired dose (mg) / Available concentration (mg/mL) = 141.5909... mg / 4 mg/mL = 35.3977... mL Round the answer to the nearest whole number. : 35.