How many mL of naproxen 125mg/5mL should a nurse administer for a dose of 500 mg?

To determine how many mL of naproxen should be administered for a dose of 500 mg when the concentration is 125 mg per 5 mL, you can set up a proportion based on the concentration.

First, identify how many mg are in 1 mL. If 125 mg is contained in 5 mL, then:

125 mg / 5 mL = 25 mg/mL.

Now, to find out how many mL are needed to achieve a dose of 500 mg, use the formula:

Desired dose (mg) = Concentration (mg/mL) x Volume (mL).

Here, we can rearrange this to find the volume:

Volume (mL) = Desired dose (mg) / Concentration (mg/mL)

Now plug in the values:

Volume (mL) = 500 mg / (25 mg/mL) = 20 mL.

Therefore, for a dose of 500 mg, the nurse should administer 20 mL of the naproxen solution. This matches the indicated answer, confirming its correctness.