Question

A hospital pharmacist is asked to determine the dose of clindamycin for a 3-day-old neonate weighing 3 lb 7 oz. In checking the literature, the pharmacist determines that the dose is listed as follows4:

<1200 g: 10 mg/kg/day divided q12h
<2000 g and 0 to 7 days old: 10 mg/kg/day divided q12h
<2000 g and >7 days old: 15 mg/kg/day divided q8h
>2000 g and 0 to 7 days old: 15 mg/kg/day divided q8h
>2000 g and >7 days old: 20 to 30 mg/kg/day divided q12h

Each divided dose is to be added to an intravenous infusion at the scheduled hour and infused over a period of 20 minutes.


The product shown in Figure 8.1 was used to prepare an IV bag containing 600 mg/50 mL of injectable solution. How many milliliters of this solution should be given for each divided dose?

Answer 1

The pharmacist should administer
`\( (4)/(5) \)` mL of the 600 mg/50 mL clindamycin solution for each divided dose.

Step-by-step explanation:

In determining the appropriate dosage for the 3-day-old neonate weighing 3 lb 7 oz, the pharmacist refers to the provided guidelines. As per the weight and age criteria, the neonate falls into the category of ">2000 g and >7 days old," requiring a dosage of 20 to 30 mg/kg/day divided q12h. To calculate the dose for this neonate, considering an average weight of 3 lb 7 oz (approximately 1.57 kg), the pharmacist uses the mid-range of the recommended dosage (25 mg/kg/day).

The next step involves determining the actual dose per administration. Since it's divided q12h, and there are two doses in a day, the dosage for each divided dose becomes
`\( (25)/(2) \)` mg/kg. To convert this dosage to milligrams, the weight of the neonate is multiplied by the dose per kilogram, resulting in
`\( (25)/(2) * 1.57 \)` mg for each divided dose. To express this in milliliters using the provided solution concentration of 600 mg/50 mL, the pharmacist divides the total dose by the concentration:
`\( ((25)/(2) * 1.57)/(600) \)` mL. The final result is
`\( (4)/(5) \)` mL for each divided dose.

In conclusion, the pharmacist should administer
`\( (4)/(5) \)` mL of the clindamycin solution, considering the neonate's weight, age, and the concentration of the injectable solution. This calculation ensures precise and safe medication administration for the neonate in accordance with the provided guidelines.