Pharmacy Technician Certification Board Practice Exam

What is the equivalent strength of levothyroxine 0.125 mg in micrograms (mcg)?

1. 1.25 mcg

2. 12.5 mcg

3. 125 mcg

4. 1,250 mcg

The correct answer is: 125 mcg

To convert milligrams to micrograms, it's important to know the relationship between the two units of measurement. One milligram (mg) is equal to 1,000 micrograms (mcg). Therefore, to find the equivalent strength of levothyroxine in micrograms, you would multiply the amount in milligrams by 1,000. In this case, 0.125 mg can be converted as follows: 0.125 mg × 1,000 mcg/mg = 125 mcg. This conversion shows that 0.125 mg of levothyroxine is equivalent to 125 micrograms, confirming that the correct choice is indeed 125 mcg. Understanding this conversion is fundamental in pharmacy practice, as accurate dosing is crucial for patient safety and medication efficacy.