A nurse is preparing to administer diphenhydramine 30 mg IM stat to a client who is having an allergic reaction. Available is diphenhydramine 50 mg/mL. How many mL should the nurse administer per dose? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
The correct answer and Explanation is :
To calculate the volume of diphenhydramine to administer, use the formula:
[
\text{Volume (mL)} = \frac{\text{Desired Dose (mg)}}{\text{Concentration (mg/mL)}}
]
In this scenario:
- Desired Dose: 30 mg
- Concentration: 50 mg/mL
Plugging in the values:
[
\text{Volume (mL)} = \frac{30 \text{ mg}}{50 \text{ mg/mL}} = 0.6 \text{ mL}
]
Thus, the nurse should administer 0.6 mL of diphenhydramine.
Explanation
Diphenhydramine is an antihistamine commonly used to treat allergic reactions. Administering the correct dose is critical for efficacy and safety. When calculating medication dosages, the concentration of the available solution is essential. In this case, the available diphenhydramine concentration is 50 mg/mL, meaning each milliliter contains 50 mg of the drug.
To find out how many milliliters correspond to the required dose of 30 mg, we divide the desired dose by the concentration. This calculation yields 0.6 mL, which indicates that the nurse needs to draw this amount from the vial to achieve the prescribed dose.
When administering medication, accuracy in measurement is vital. Nurses must ensure they are using the correct units and rounding as specified in guidelines (in this case, rounding to the nearest tenth). The use of leading zeros before decimals (0.6 instead of .6) is also important in medication administration to avoid confusion, particularly in situations where quick decisions are necessary.
Administering the correct volume ensures the effectiveness of the medication in alleviating the allergic reaction while minimizing the risk of adverse effects from an incorrect dose. Always double-check calculations and consult with a pharmacist or use clinical guidelines if there is any uncertainty.