Answer:
3.06 mL ampicillin IV per individual dose
≈ 3 mL
Explanation:
The first step in this dosage calculation is to determine how much of the antibiotic medication ampicillin is to be administered daily according the the patient's weight in kilograms, doing so by multiplying the ordered amount by said weight.
The ordered amount is the quantity of medication written and prescribed by a provider, typically a doctor. In this case, the ordered amount is 300 mg/kg/day.
300 mg/kg/day × 10.2kg
kg in the numerator and denominator will cancel each other out, leaving mg per day (mg/day) as the remaining units.
300 mg/day × 10.2 = 3060 mg/day
Using this rate and written frequency at which a dose of medication is to be administered, the individual dose amount can be determined. 1 day is equivalent to 24 hours (1 day = 24 hr), so the ordered amount can be changed from 3060 mg/day to 3060mg/24hr.
The prescription states an individual dose is to be administered every 6 hours (q6h). Multiplying the ordered amount per day by this frequency at which a dose must be administered yields the individual dose amount.
3060 mg/24hr × 6hr
hr in both numerator and denominator cancel each other out, leaving mg as the remaining unit.
3060 mg/24 × 6
= 3060 mg(6) ÷ 24
= 18360 mg ÷ 24
= 765 mg
The last step is to use this new ordered dose of 765 mg and multiply by the dosage strength in order to determine the volume of ampicillin to administer to the patient. The following formula represents this calculation:
ordered amount × dosage strength = amount to administer
The dosage strength is the concentration of medication available from the pharmacy's stock of medications, usually represented as a proportion, such as mg/mL. In this case, it is 1g/4mL. 1g is also equivalent to 1000 mg, so the dosage strength can also be represented as 1000 mg/4mL.
765 mg × (4 mL/1000 mg)
mg in both numerator and denominator cancel each other out, leaving mL as the remaining unit.
= (765 × 4 mL) / 1000
= 3060 mL / 1000
= 3.06 mL
≈ 3 mL
The patient should be administered 3.06 mL ampicillin IV q6h, or approximately 3 mL ampicillin IV