A nurse is preparing to administer naproxen 500 mg PO BID for a client who has osteoarthritis. The amount available is naproxen 125 mg/5 mL oral suspension. How many mL should the nurse administer per dose? (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 the nurse should administer per dose, we use the formula:
[
\text{Volume to administer} = \left( \frac{\text{Desired dose}}{\text{Available dose}} \right) \times \text{Available volume}
]
Step 1: Identify key values.
- Desired dose (the dose the provider ordered): 500 mg
- Available dose: 125 mg in 5 mL of the suspension
Step 2: Set up the equation.
[
\text{Volume to administer} = \left( \frac{500 \text{ mg}}{125 \text{ mg}} \right) \times 5 \text{ mL}
]
Step 3: Calculate the ratio.
[
\frac{500 \text{ mg}}{125 \text{ mg}} = 4
]
Step 4: Multiply by the available volume.
[
4 \times 5 \text{ mL} = 20 \text{ mL}
]
Thus, the nurse should administer 20 mL of the suspension per dose.
Explanation:
Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) often used to manage pain and inflammation in conditions like osteoarthritis. The physician has ordered 500 mg of naproxen to be administered twice a day (BID). Since the available form of naproxen is an oral suspension of 125 mg per 5 mL, we need to figure out how many milliliters are required to achieve the 500 mg dose.
By dividing the desired dose (500 mg) by the concentration of the suspension (125 mg per 5 mL), we determine how many “sets” of the available concentration are needed. Each set corresponds to 5 mL of liquid. After solving the calculation, the nurse needs to administer 20 mL for the 500 mg dose. Rounding is unnecessary as the calculation yields a whole number.
This precise calculation ensures accurate medication administration, reducing the risk of underdosing or overdosing the client.