An adult client receives a prescription for diphenhydramine 15 mL by mouth every 12 hours PRN for pruritus. The bottle is labeled, diphenhydramine 12.5 mg/5 mL. What is the total daily dose in mg that the client receives? (Enter numerical value only.)

Identify given information: Dose per administration = 15 mL Frequency = 2 times per day (every 12 hours) Concentration = 12.5 mg per 5 mL Convert mL to mg using the concentration: (15 mL × 12.5 mg) ÷ 5 mL = 37.5 mg per dose Calculate the total daily dose: 37.5 mg × 2 doses per day = 75 mg So the total daily dose the nurse should administer is 75 mg.