Which of the following is equivalent to 0.4 mg in micrograms?

To convert milligrams to micrograms, it is important to understand the relationship between these two units of measurement. One milligram is equal to 1,000 micrograms. Therefore, to convert 0.4 milligrams to micrograms, you multiply by 1,000.

So, the calculation is as follows:

0.4 mg x 1,000 mcg/mg = 400 mcg.

This shows that 0.4 mg is equivalent to 400 micrograms, making the correct answer 400 mcg. Converting properly between metric units is crucial in the pharmacy field, as dosing errors can lead to significant patient safety issues. Understanding this conversion helps ensure that medications are dispensed in the correct dosages.