How many milliliters of meperidine (Demerol) should be administered if 12.5mg is ordered and it is available in a concentration of 50mg/1ml?

To determine the correct volume of meperidine to administer, you first need to understand the concentration of the medication available. The concentration given is 50 mg per 1 mL. This means that in every milliliter of the solution, there are 50 mg of meperidine.

To find out how many milliliters are needed for a dose of 12.5 mg, you can set up a proportion based on the concentration.

You can use the formula:

[

\text{Volume (mL)} = \frac{\text{Desired Dose (mg)}}{\text{Concentration (mg/mL)}}

]

Plugging in the values:

[

\text{Volume (mL)} = \frac{12.5 , \text{mg}}{50 , \text{mg/mL}} = 0.25 , \text{mL}

]

This calculation shows that to administer 12.5 mg of meperidine, you need to give 0.25 milliliters of the solution, making this the correct answer. Understanding how to manipulate concentrations and convert between doses and volumes is crucial in the clinical setting to ensure safe and accurate medication administration.