85. A patient who weighs 154 lb has a medication order for amphotericin B. The dosage of 0.25 mg/kg is to be added to 500 mL of D5W. How much amphotericin B in mg is needed to fill the order?
Answer: B
17.5 mg of amphotericin B is needed to fill the order.
To determine the required dosage of amphotericin B for a patient weighing 154 lb, we first convert the weight from pounds to kilograms. The calculation shows that 0.25 mg/kg corresponds to a total dosage of 17.5 mg for this patient.
A) 7.5
This option incorrectly suggests that the dosage is 7.5 mg. To arrive at that figure, one would need to miscalculate the weight conversion or the dosage calculation, which does not reflect the accurate requirement of 0.25 mg/kg.
B) 17.5
This option is correct as it accurately reflects the calculation based on the patient's weight. Converting 154 lb to kg (approximately 70 kg), the dosage of 0.25 mg/kg results in 17.5 mg, which aligns with the medication order.
C) 75
Choosing 75 mg is incorrect because it exceeds the calculated requirement substantially. This choice may stem from misunderstanding the dosage per weight unit, as it does not align with the prescribed dosage of 0.25 mg/kg.
D) 175
This option is also incorrect, as 175 mg far exceeds the necessary dosage calculated for the patient. Such a high dosage implies a significant miscalculation in understanding the weight-based dosing of amphotericin B.
Conclusion
The correct dosage of 17.5 mg is derived from properly converting the patient's weight and applying the specified dosage correctly. Other options fail to reflect accurate calculations or misinterpret the dosage requirements based on the patient's weight, confirming that only option B is valid.