A nurse is preparing to administer phenytoin suspension 300 ?mg PO, ?twice per day. The amount available is phenytoin suspension 125 ?mg/5 ?mL. ?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 need to follow these steps:
Step 1: Understand the given information
The order is for 300 mg of phenytoin to be administered twice per day. The available concentration is 125 mg per 5 mL.
Step 2: Use the formula for dose calculation
The formula to determine the volume of the medication to be administered is: Volume to be administered (mL)=Desired dose (mg)Concentration (mg/mL)\text{Volume to be administered (mL)} = \frac{\text{Desired dose (mg)}}{\text{Concentration (mg/mL)}}
Step 3: Find the concentration in mg/mL
The available concentration is 125 mg per 5 mL. To convert this into mg/mL, divide the total milligrams by the volume in milliliters: 125 mg5 mL=25 mg/mL\frac{125 \, \text{mg}}{5 \, \text{mL}} = 25 \, \text{mg/mL}
This means each milliliter contains 25 mg of phenytoin.
Step 4: Calculate the volume needed for the 300 mg dose
Now, we substitute the desired dose (300 mg) and the concentration (25 mg/mL) into the formula: Volume to be administered=300 mg25 mg/mL=12 mL\text{Volume to be administered} = \frac{300 \, \text{mg}}{25 \, \text{mg/mL}} = 12 \, \text{mL}
Step 5: Round to the nearest whole number
In this case, the result is already a whole number (12 mL). Therefore, the nurse should administer 12 mL of phenytoin suspension per dose.
Final Answer:
The nurse should administer 12 mL per dose.
Explanation
By dividing the total amount of the drug to be administered (300 mg) by the concentration of the drug (25 mg/mL), the nurse can determine the exact volume of medication to be given. This ensures that the patient receives the correct amount of medication, as prescribed. It’s essential for healthcare professionals to accurately calculate doses to ensure patient safety and effectiveness of the medication.