54. The initial dosage of a drug is 5 mg/kg of body weight. If a patient weighs 84 kg, what is the initial dosage in mg?
Answer: C
The initial dosage for a patient weighing 84 kg is 420 mg.
To calculate the initial dosage, you multiply the patient's weight by the dosage per kilogram: 5 mg/kg × 84 kg = 420 mg.
A) 81.4
This option is incorrect as it does not reflect the proper calculation. If you divide the total dose by the weight, it leads to an erroneous figure that does not align with the required dosage calculation.
B) 185
This option is also incorrect. The calculation of 5 mg/kg for a weight of 84 kg would not yield this amount; rather, it significantly underestimates the initial dosage required for the patient.
C) 420
This option is correct as it accurately represents the initial dosage calculated by multiplying the patient’s weight by the specified dosage per kilogram: 5 mg × 84 kg = 420 mg.
D) 925
This option is incorrect because it overestimates the required dosage. The calculation based on the patient’s weight and the dosage per kilogram does not support this figure.
Conclusion
The calculation clearly indicates that the correct initial dosage for a patient weighing 84 kg is 420 mg, derived from the formula of 5 mg/kg. All other options either significantly underestimate or overestimate the required dosage, demonstrating a misunderstanding of the weight-based dosage calculation.