Question

You want to give 5mg/kg of ampicillin to a child weighing 65 pounds. How many mls will you give if there is 50mg/ml on hand?

Choose one answer.

a. 3 mls
b. 2.9 mls
c. 2.96 mls
d. 2.95 mls

Answer 1

After converting the child's weight from pounds to kilograms, and calculating the total milligrams of ampicillin needed based on the prescribed dosage, the volume in milliliters is determined by dividing by the medicine's concentration. The result is
`2.95 mls`.

Step-by-step explanation:

To calculate the correct dosage of ampicillin for a child, we first need to convert the child's weight from pounds to kilograms, and then use the dosage instructions to determine the total milligrams needed which will finally be converted to milliliters based on the concentration of the medicine on hand.

First, convert the weight from pounds to kilograms:

`1 pound = 0.453592 kg`

`65 pounds = 65 * 0.453592 kg`

`65 pounds = 29.48448 kg`

Now, calculate the total dosage required in milligrams:

`5 mg/kg * 29.48448 kg = 147.4224 mg`

With a concentration of 50 mg/ml on hand, calculate the volume in milliliters:

`147.4224 mg / 50 mg/ml = 2.948448 ml`

So, rounded to two decimal places, you will give
`2.95 mls` of ampicillin to the child.

The correct option is d.
`2.95 mls`.