A nurse is preparing to administer ondansetron 4 mg IM stat. The amount available is ondansetron for injection 2 mg/mL. How many mL should the nurse administer? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
The correct answer and Explanation is :
To determine how many mL of ondansetron to administer, you can use the formula:
[
\text{Volume (mL)} = \frac{\text{Desired Dose (mg)}}{\text{Available Concentration (mg/mL)}}
]
In this case, the desired dose of ondansetron is 4 mg, and the available concentration is 2 mg/mL.
Substituting the values into the formula:
[
\text{Volume (mL)} = \frac{4 \text{ mg}}{2 \text{ mg/mL}} = 2 \text{ mL}
]
So, the nurse should administer 2 mL of ondansetron.
Explanation:
- Understanding the Dosage Calculation: This calculation is essential in nursing and pharmacology to ensure patients receive the correct medication dose. Accurate dosing is crucial for efficacy and safety.
- Desired Dose vs. Available Concentration: The “desired dose” refers to the amount prescribed by a physician or required for treatment. The “available concentration” indicates how much of the drug is present in each mL of the solution. Understanding these terms helps in performing accurate calculations.
- Performing the Calculation: By dividing the desired dose by the available concentration, you convert the required medication amount into a volume (in mL). Here, you calculated how many mL of a solution are needed to achieve the therapeutic effect intended with 4 mg of ondansetron.
- Rounding Rules: The instructions specify rounding to the nearest whole number and using a leading zero if needed. In this case, the answer (2 mL) already meets this requirement.
- Importance of Accuracy: In a clinical setting, administering the wrong dose can lead to under-treatment or potential overdose, so mastering these calculations is vital for patient safety.
This precise calculation ensures that the patient receives the appropriate medication dose quickly, particularly in urgent situations, such as those requiring an immediate intervention for nausea or vomiting.