40. Travoprost Z is to be used 1 drop b.i.d. in each eye. Using a 2.5 mL bottle containing 100 drops/mL, how many bottles will be required to fill this prescription to provide 60 days of treatment?
Answer: B
Five bottles will be required to fill this prescription for 60 days of treatment.
To determine the number of bottles needed, we first calculate the total number of drops required for 60 days. Since 1 drop is administered twice a day in each eye, that amounts to 120 drops over 60 days. Given that each bottle contains 250 drops (2.5 mL at 100 drops/mL), we find that 5 bottles are necessary to meet the prescription.
A) 4
Choosing 4 bottles would yield a total of 1,000 drops (4 bottles × 250 drops/bottle), which exceeds the required 720 drops needed for the 60-day treatment. Therefore, this option is incorrect.
B) 5
This option is correct as it provides the exact number of bottles needed for the prescribed dosage over the treatment period. With 5 bottles, there would be a total of 1,250 drops available, which is sufficient for the 720 drops required.
C) 120
This option is not feasible since it greatly exceeds the amount needed for the treatment. The calculation of 120 bottles would provide 30,000 drops, which is unnecessary and impractical for a 60-day regimen requiring only 720 drops.
D) 240
Selecting 240 bottles is excessive, offering 60,000 drops, far beyond what is required for the treatment plan. This option is clearly incorrect as it does not align with the prescription needs.
Conclusion
The calculation confirms that 5 bottles are required to provide 60 days of treatment, as they adequately supply the necessary 720 drops. All other options either fall short or significantly exceed the quantity of drops needed, making them incorrect choices in this context.