A nurse is administering medications to a client who weighs 132 lb. The prescription reads chloramphenicol, 50mg/kg/day in 4 divided doses. Available is chloramphenicol 100 mg/mL. How many mL should the nurse give with each 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 amount of chloramphenicol to administer per dose, follow these steps:
- Convert the client’s weight from pounds to kilograms: The weight conversion factor is 1 kg = 2.2 lb. Therefore:Weight in kg=132 lb2.2 lb/kg=60 kg\text{Weight in kg} = \frac{132 \text{ lb}}{2.2 \text{ lb/kg}} = 60 \text{ kg}Weight in kg=2.2 lb/kg132 lb=60 kg
- Calculate the total daily dose of chloramphenicol required: The prescription is 50 mg/kg/day. For a 60 kg client:Total daily dose=50 mg/kg/day×60 kg=3000 mg/day\text{Total daily dose} = 50 \text{ mg/kg/day} \times 60 \text{ kg} = 3000 \text{ mg/day}Total daily dose=50 mg/kg/day×60 kg=3000 mg/day
- Determine the dose per administration (since it’s divided into 4 doses a day):Dose per administration=3000 mg/day4=750 mg/dose\text{Dose per administration} = \frac{3000 \text{ mg/day}}{4} = 750 \text{ mg/dose}Dose per administration=43000 mg/day=750 mg/dose
- Convert the dose into mL using the available concentration (100 mg/mL): The concentration of the solution is 100 mg/mL, so:Volume required=750 mg100 mg/mL=7.5 mL\text{Volume required} = \frac{750 \text{ mg}}{100 \text{ mg/mL}} = 7.5 \text{ mL}Volume required=100 mg/mL750 mg=7.5 mL
Thus, the nurse should administer 7.5 mL of chloramphenicol per dose.
Explanation:
- Weight Conversion: To accurately calculate medication dosages, converting the client’s weight from pounds to kilograms is necessary because drug dosages are often prescribed in mg/kg. Weight in pounds (lb) is converted to kilograms (kg) using the factor 1 kg = 2.2 lb.
- Daily Dose Calculation: The prescription specifies the total daily dose based on the client’s weight. Multiplying the weight in kg by the dosage per kg provides the total daily dose needed.
- Dividing the Daily Dose: Since the medication is to be given in divided doses throughout the day, the total daily dose must be divided by the number of doses per day. This gives the amount of medication to be administered per dose.
- Volume Calculation: With the concentration of the available medication, the required volume is calculated by dividing the dose to be administered by the concentration. This step ensures that the correct volume of medication is administered to achieve the prescribed dose.
This method ensures accurate dosing and proper medication management for the client.