The healthcare provider prescribes hydroxyzine 35 mg IM for a client who is vomiting. The available drug is labeled 50 mg/mL. How many mL should the nurse administer? (Enter numerical value only. If rounding is required, round to the nearest tenth.)
The Correct Answer and Explanation is:
To determine the correct volume of hydroxyzine to administer, you need to use the formula for dosage calculation:
Volume to administer (mL)=Desired Dose (mg)Concentration (mg/mL)\text{Volume to administer (mL)} = \frac{\text{Desired Dose (mg)}}{\text{Concentration (mg/mL)}}Volume to administer (mL)=Concentration (mg/mL)Desired Dose (mg)
In this case:
- Desired Dose: 35 mg
- Concentration: 50 mg/mL
Plugging these values into the formula:
Volume to administer (mL)=35 mg50 mg/mL\text{Volume to administer (mL)} = \frac{35 \text{ mg}}{50 \text{ mg/mL}}Volume to administer (mL)=50 mg/mL35 mg
Volume to administer (mL)=0.7 mL\text{Volume to administer (mL)} = 0.7 \text{ mL}Volume to administer (mL)=0.7 mL
So, the nurse should administer 0.7 mL.
Explanation:
- Understanding Dosage Calculation: Dosage calculation involves determining how much of a medication to give based on the concentration of the drug and the prescribed dose. In this situation, hydroxyzine is available in a concentration of 50 mg/mL, which means each milliliter contains 50 milligrams of hydroxyzine.
- Using the Formula: The formula Desired Dose (mg)Concentration (mg/mL)\frac{\text{Desired Dose (mg)}}{\text{Concentration (mg/mL)}}Concentration (mg/mL)Desired Dose (mg) helps convert the prescribed dose into the volume needed from the stock concentration. For the prescribed dose of 35 mg and a concentration of 50 mg/mL, you divide 35 mg by 50 mg/mL to find out how many milliliters contain the desired dose.
- Calculation Steps:
- First, identify the amount of medication required (35 mg).
- Determine the concentration of the medication available (50 mg/mL).
- Use the formula to calculate the volume: 35 mg50 mg/mL=0.7 mL\frac{35 \text{ mg}}{50 \text{ mg/mL}} = 0.7 \text{ mL}50 mg/mL35 mg=0.7 mL.
- Rounding: The result, 0.7 mL, is already in its simplest form. If rounding were necessary, it would be to the nearest tenth, which is not needed in this case.
Thus, the nurse should administer 0.7 mL of hydroxyzine to provide the correct dose of 35 mg.