Question

A nurse practitioner prepares an injection of promethazine, an antihistamine used to treat allergic rhinitis. If the stock bottle is labeled 25 mg/mL and the order is a dose of 14.5 mg , how many milliliters will the nurse draw up in the syringe?

Answer 1

For this problem, let's use the approach of dimensional analysis. This technique is done by cancelling out like units that appear both on the numerator and the denominator side. As a result, this technique will let you know that your final answer conforms to what parameter is asked. In this case, the final answer should be in mL. The solution is as follows:

14.5 mg * 1 mL/25 mg = 0.58 mL

Answer 2

Answer : 0.58 mL will the nurse draw up in the syringe.

Explanation :

As we are given that the stock bottle labelled 25 mg/mL. Now we have to calculate the amount will nurse draw up in the syringe.

As, 25 mg dose present in = 1 mL

and, 1 mg dose present in = $\frac{1mg}{25mg}\times 1mL$

So, 14.5 mg dose present in = $\frac{14.5mg}{25mg}\times 1mL$

                                               = 0.58 mL

Therefore, 0.58 mL will the nurse draw up in the syringe.