70. Caiculator Aprescription order is written for 40 mg of a drug. It is available in a 10 mL vial with a concentration of 25 mg/mL. How many mL are needed for the ordered dose?
Answer: B
1.6 mL are needed for the ordered dose.
To achieve the prescribed dosage of 40 mg from a solution with a concentration of 25 mg/mL, a volume of 1.6 mL must be administered.
A) 0.625
Option A is incorrect because 0.625 mL would only deliver 15.625 mg of the drug, which is significantly less than the required 40 mg. This calculation does not meet the prescription order.
B) 1.6
Option B is correct as it accurately calculates the required volume to administer 40 mg. By dividing the prescribed dose (40 mg) by the concentration (25 mg/mL), we find that 1.6 mL is needed (40 mg ÷ 25 mg/mL = 1.6 mL).
C) 6.25
Option C is incorrect because 6.25 mL would provide 156.25 mg of the drug, which exceeds the ordered dose of 40 mg. This volume would result in an overdosage.
D) 16
Option D is also incorrect since administering 16 mL would result in a delivery of 400 mg of the drug. This is considerably higher than the prescribed dose and would pose a risk of overdose.
Conclusion
The correct answer of 1.6 mL is derived from the proper calculation based on the drug's concentration and the ordered dose. All other options fail to meet the prescribed amount, either delivering too little or far exceeding the required dosage. Thus, 1.6 mL is the only viable option to fulfill the prescription accurately.