A nurse is preparing to administer perphenazine 200 mg divided into four equal doses daily to a client who has psychosis. Available is perphenazine oral solution16 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 trailing zeros.)
The Correct Answer and Explanation is:
To determine the amount of perphenazine oral solution to administer per dose, we first need to break down the total daily dose into the per-dose amount. The nurse is instructed to administer a total of 200 mg of perphenazine daily, divided into four equal doses.
Step 1: Calculate the Per-Dose Amount
The total daily dose is 200 mg, and it is divided into four doses.Per-dose amount=Total daily doseNumber of doses=200 mg4=50 mg\text{Per-dose amount} = \frac{\text{Total daily dose}}{\text{Number of doses}} = \frac{200 \, \text{mg}}{4} = 50 \, \text{mg}Per-dose amount=Number of dosesTotal daily dose=4200mg=50mg
Step 2: Convert the Per-Dose Amount to mL
The available concentration of perphenazine is 16 mg/mL. To find out how many mL are needed for a 50 mg dose, we can set up the following equation:Volume (mL)=Desired dose (mg)Concentration (mg/mL)\text{Volume (mL)} = \frac{\text{Desired dose (mg)}}{\text{Concentration (mg/mL)}}Volume (mL)=Concentration (mg/mL)Desired dose (mg)
Substituting the values:Volume (mL)=50 mg16 mg/mL=3.125 mL\text{Volume (mL)} = \frac{50 \, \text{mg}}{16 \, \text{mg/mL}} = 3.125 \, \text{mL}Volume (mL)=16mg/mL50mg=3.125mL
Step 3: Rounding the Answer
The problem specifies to round to the nearest tenth. Therefore:3.125 mL≈3.1 mL3.125 \, \text{mL} \approx 3.1 \, \text{mL}3.125mL≈3.1mL
Conclusion
The nurse should administer 3.1 mL of the perphenazine oral solution per dose.
Explanation of the Process
Calculating medication dosages accurately is crucial in nursing practice, particularly with psychotropic medications, where precise dosing is necessary to achieve therapeutic effects while minimizing side effects. This calculation involves understanding how to divide a total daily dose into smaller, manageable doses based on the prescribed frequency. In this case, we ensured that the total daily amount aligns with the concentration of the available medication. Understanding the conversion from mg to mL is essential, as liquid medications often require such calculations, especially in cases where precise dosing impacts patient outcomes. Proper rounding also plays a role in maintaining medication safety and efficacy.