A child who weighs 18 pounds recieves a prescription for amoxicillin 25 mg/kg/day by mouth in divided doses every 12 hours. The bottle labeled, "Amoxicillin for Oral Suspension, USP 400 mg per 5 mL." How many mL should the nurse administer with each dose? (Enter numerical value only. If rounding is required, round to the nearest tenth.)
Explanation & Rationale
Given: Ordered dose of amoxicillin: 25 mg/kg/day Child's weight: 18 pounds Concentration of amoxicillin suspension: 400 mg/5 mL Step 1: Convert child's weight from pounds to kilograms: 1 pound (lb) = 0.453592 kilograms (kg) Child's weight in kg = 18 lbs x 0.453592 kg/lb = 8.164656 kg Step 2: Calculate the total daily dose of amoxicillin: Total daily dose (mg) = Ordered dose (mg/kg/day) x Child's weight (kg) Total daily dose (mg) = 25 mg/kg/day x 8.164656 kg Total daily dose (mg) = 204.1164 mg/day Step 3: Calculate the dose per administration: Since the medication is given every 12 hours, there are 2 administrations per day. Dose per administration (mg) = Total daily dose (mg) / Number of administrations per day Dose per administration (mg) = 204.1164 mg/day / 2 administrations/day Dose per administration (mg) = 102.0582 mg Step 4: Calculate the volume to be administered per dose: Volume (mL) = Dose per administration (mg) / Concentration (mg/mL) Volume (mL) = 102.0582 mg / (400 mg/5 mL) Volume (mL) = 102.0582 mg x (5 mL / 400 mg) Volume (mL) = 1.2757275 mL Step 5: Round to the nearest tenth: Volume (mL) ≈ 1.3 mL