Physician ordered dose: Pentamidine 3mg/kg daily
Dose available: pentamidine 60 mg/mL
How many mL should be administrated for a child, weight 88 lb?
The correct answer and explanation is :
Calculation of the Dose
- Convert Weight from Pounds to Kilograms:
[
88 \text{ lb} \div 2.2 = 40 \text{ kg}
] - Determine the Required Dose:
The physician ordered 3 mg/kg daily:
[
3 \text{ mg} \times 40 \text{ kg} = 120 \text{ mg}
] - Calculate the Volume in mL to Administer:
The available concentration is 60 mg/mL, so:
[
120 \text{ mg} \div 60 \text{ mg/mL} = 2 \text{ mL}
]
Final Answer:
The correct dose to administer is 2 mL of Pentamidine 60 mg/mL.
Explanation
Medication dosage calculations are crucial in healthcare to ensure patient safety and effectiveness of treatment. Here, we calculate the correct dosage for an 88-pound child prescribed Pentamidine 3 mg/kg daily with a concentration of 60 mg/mL.
First, converting weight from pounds to kilograms is essential since medication doses are based on the metric system. We use the standard conversion factor (1 kg = 2.2 lb) to determine the child’s weight in kilograms (40 kg).
Next, applying the ordered dose (3 mg/kg), we calculate the total required dose:
[
3 \text{ mg} \times 40 \text{ kg} = 120 \text{ mg}
]
This tells us how much active drug the child needs.
Since the drug is available in a concentration of 60 mg/mL, we divide the required 120 mg by 60 mg/mL to find the appropriate volume to administer:
[
120 \text{ mg} \div 60 \text{ mg/mL} = 2 \text{ mL}
]
Accurate dosage calculations prevent overdosing, which can cause toxicity, or underdosing, which can reduce effectiveness. Double-checking conversions and calculations ensures the safest care for pediatric patients.
