Question

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.

Answer 1

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.

Answer 2

75 Days