A prescription calls for the 4% Pilocar with a Sig. of "gtt i OU tid". How many 15-ml bottles should be dispensed for a 90 days supply if the eye drop bottle delivers 20 drops per ml?

Somehow, it is a bit confusing.

I tried: 1 bottle/ml soln * ml soln/20 drops * 3 drops (gtt three times daily)/day * 90 days. But my answer is wrong. The most I can do is round up and come up with 2 bottles. Am not sure. Pls help.

OU means both eyes. So, you need to administer drops to both eyes, three times daily for a total of Six drops. That will give you a final answer of 27 mL, requiring that you need two 15-mL bottles to be dispensed.

75 Days

To calculate the number of 15-ml bottles that should be dispensed for a 90-day supply of the 4% Pilocar eye drops with a Sig. of "gtt i OU tid", you need to consider the following steps:

Step 1: Determine the total number of drops required for 90 days
Since the Sig. (prescription instructions) states "gtt i OU tid", it means that you need to take 1 drop in each eye (OU) three times a day (tid). Hence, the total number of drops required for 90 days can be calculated as follows:
1 drop (OU) * 3 drops (tid) * 90 days = 270 drops

Step 2: Convert drops to milliliters (ml)
Given that the eye drop bottle delivers 20 drops per ml, you can convert the number of drops to milliliters as follows:
270 drops / 20 drops per ml = 13.5 ml

Step 3: Determine the number of 15-ml bottles needed
To determine the number of 15-ml bottles needed, divide the total volume required (13.5 ml) by the volume per bottle (15 ml):
13.5 ml / 15 ml per bottle = 0.9 bottles

Since you cannot dispense a fraction of a bottle, you need to round up to the nearest whole number. Therefore, you should dispense 1 bottle for a 90-day supply of the 4% Pilocar eye drops.

To determine the number of 15-ml bottles needed to dispense a 90-day supply of the medication, you need to calculate the total number of drops required for the entire duration.

First, let's break down the Sig. (short for Signatura) "gtt i OU tid":
- "gtt" stands for "guttae," which is Latin for "drops".
- "i" represents the number of drops, which in this case, is one drop.
- "OU" is an abbreviation for "oculus uterque," meaning "both eyes".
- "tid" stands for "ter in die," indicating that the medication is to be taken three times a day.

To calculate the total number of drops needed for a 90-day supply, you can use the following formula:

Total Drops = Drops per Day x Frequency x Number of Days

In this case:
- Drops per Day = 1 drop (gtt i)
- Frequency = 3 times a day (tid)
- Number of Days = 90 days

Total Drops = 1 drop x 3 times per day x 90 days = 270 drops

Now that we know we need a total of 270 drops, we can calculate the number of 15-ml bottles required.

Since there are 20 drops per ml, we need to convert the total number of drops to milliliters:

Total ml = Total Drops / Drops per ml = 270 drops / 20 drops per ml = 13.5 ml

Since each bottle contains 15 ml, we round up to the nearest whole number to ensure we have enough medication for the full duration:

Number of Bottles = Total ml / ml per bottle = 13.5 ml / 15 ml per bottle ≈ 0.9 bottles

Rounding up, we find that you should dispense 1 bottle to provide a 90-day supply of the medication.