Question

recommended dose of antibiotic is 50 - 75 mg/kg/24h divided q8h iv per syringe. an infant weighs 3 kg.
what is the low recommended dose for this child per day?
mg/day (if decimal, round to the tenth place.)
what is the high recommended dose for this child per day?
mg/day (if decimal, round to the tenth place.)
what is the low recommended single dose for this child?
mg (if decimal, round to the tenth place.)
what is the high recommended single dose for this child?
mg (if decimal, round to the tenth place.)

Explanation:

Step1: Calculate low daily dose

Multiply the infant's weight by the low dose per kg.
$$3\times50 = 150$$

Step2: Calculate high daily dose

Multiply the infant's weight by the high dose per kg.
$$3\times75=225$$

Step3: Calculate low single - dose

Divide the low daily dose by the number of doses per day ($24\div8 = 3$ doses per day).
$$150\div3=50$$

Step4: Calculate high single - dose

Divide the high daily dose by the number of doses per day.
$$225\div3 = 75$$

Answer:

150 mg/day
225 mg/day
50 mg
75 mg