A medication is prescribed at a dose of 500 micrograms (mcg). If the medication is supplied as a solution with a concentration of 1 mg/mL, how many milliliters (mL) are needed to provide the prescribed dose?

• A. 50 mL
• B. 0.5 mL
• C. 0.05 mL
• D. 5 mL

Answer: (B)

Verified step by step guidance

1. Identify the given information: the prescribed dose is 500 micrograms (mcg), and the medication concentration is 1 milligram per milliliter (mg/mL).
2. Convert the prescribed dose from micrograms to milligrams to match the units of concentration. Recall that 1 mg = 1000 mcg, so use the conversion: \(\text{dose in mg} = \frac{500\ \text{mcg}}{1000}\).
3. Set up the relationship between volume and concentration using the formula: \(\text{Volume (mL)} = \frac{\text{Dose (mg)}}{\text{Concentration (mg/mL)}}\).
4. Substitute the converted dose and the concentration into the formula: \(\text{Volume (mL)} = \frac{\text{dose in mg}}{1\ \text{mg/mL}}\).
5. Calculate the volume needed to deliver the prescribed dose by performing the division, which will give the volume in milliliters.