A reconstituted solution containing 500 mg of ganciclovir in 20 ml of sterile water for injection is added to 500 ml of 5% dextrose in water. the infusion is to be administered over 2 hours. if the infusion set delivers 15 drops/ml, what should the flow rate be to administer the bag over the designated time interval?

The flow of rate that you are asked for is the number of drops per time unit.

Usually it is counted the number of drops per minute, so I will aim to that.

1) Calculate the total volume.

Assuming additive volumes = > final volume = volume of sterile water + volume of the dextrose solution

Final volume = 20 ml + 500 ml = 520 ml.

2) Calculate the number of drops in 520 ml, given that there are 15 drops in 1 ml:

=> 520 ml * 15 drops / ml = 7800 drops.

3) That must be administered over 2 hours, which is 120 minutes.

So, calculate the flow rate as the number of drops divided by the time in minutes:

flow rate = 7800 drops / 120 minutes = 65 drops / minute.

Answer: 65 drops / minute