If a medication is available in a concentration of 2 mg/mL, how many mL are needed for a 40 mg dose?

To determine how many mL are needed for a 40 mg dose when the medication is available in a concentration of 2 mg/mL, you can use a simple calculation based on the dosage and concentration.

Start by using the formula:

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

In this case, the dose required is 40 mg and the concentration of the medication is 2 mg/mL. Plugging in the values:

[ \text{Volume (mL)} = \frac{40 \text{ mg}}{2 \text{ mg/mL}} ]

This calculation simplifies to:

[ \text{Volume (mL)} = 20 \text{ mL} ]

Thus, for a dose of 40 mg, you would need 20 mL of the medication. The answer is based on straightforward arithmetic, where you are directly determining how many milliliters are required to achieve the desired dose based on the concentration available. This approach is essential in pharmacy practice to ensure that patients receive the correct amount of medication.