An adult client receives a prescription for diphenhydramine 15 mL PO 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.)

Dose per administration in milliliters = 15 mL. Concentration of the medication = 12.5 mg/5 mL. Calculate the amount of medication in milligrams (mg) per administration. Amount per administration (mg) = Dose per administration (mL) × (Concentration (mg) / Volume (mL)) = 15 mL × (12.5 mg / 5 mL) = 15 mL × 2.5 mg/mL = 37.5 mg. Determine the number of doses per day. Doses are given every 12 hours, so Number of doses per day = 24 hours / 12 hours/dose = 2 doses/day. Calculate the total daily dose in milligrams (mg). Total daily dose (mg) = Amount per administration (mg) × Number of doses per day = 37.5 mg × 2 doses = 75 mg.