It depends on how much you are taking twice a day by: David
If you are prescribed 5ml BID (twice a day) then that means you would be consuming 10ml daily, and 250ML divided by 10 is 25. If these directions are correct and reflect your directions then your cough medicine bottle would last 25 days at these directions.
Since there are many other possible scenarios as to what your directions could be, I can't really answer this question with certainty.
It would be best to submit another question to this website with more of the relevant information and I will certainly answer it for you!
Thank you for understanding, and for your question!
Patient is prescribed 10g of Glucose. The glucose is presented as a 5% solution in 500ml Saline. How much of the 5% dextrose saline solution do you need