A nurse is preparing to administer methimazole 0.3 mg/kg/day PO divided in equal doses every 8 hr to a school-age child who weighs 55 lb. Available is methimazole 5 mg tablets. How many tablets should the nurse administer per dose? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)

Calculation: Convert the child's weight from pounds (lb) to kilograms (kg) using the conversion factor of 2.2 lb/kg. Patient's weight in kg = 55 lb / 2.2 lb/kg = 25 kg. Calculate the total daily dose in milligrams (mg) for the child. Total daily dose = Ordered dose (mg/kg/day) × Patient's weight (kg) = 0.3 mg/kg/day × 25 kg = 7.5 mg/day. Calculate the dose per administration (every 8 hr, which is 3 doses per day). Dose per administration = Total daily dose (mg/day) / 3 doses/day = 7.5 mg / 3 = 2.5 mg/dose. Available tablet strength = 5 mg. Calculate the number of tablets to administer per dose. Tablets per dose = Dose per administration (mg) / Available tablet strength (mg/tablet) = 2.5 mg / 5 mg/tablet = 0.5 tablets.