# IV math for Pharmacy Tech Test

by Cliff
(Texas)

A patient is receiving an infusion that started at 1400 hours. The bag used contained 500mL of 0.25% active drug in 0.9% NaCl. The infusion pump was set to deliver 75mL/Hr. The surgeon ordered that the infusion run until the patient receive 750mg of the active drug. What time will the infusion be terminated?

A. 5:00 P.M.
B. 7:00 P.M.
C. 10:00 P.M.
D. 12:00 A.M.

### Comments for IV math for Pharmacy Tech Test

 Infusion question by: Brad Wojcik, Pharm D I come up with 6 pm. 750 mg/(100 ml/0.25 g)(1 g/1000 mg)(1 H/75 mL) = 4 h1400 h + 4 h = 1800 h or 6 pm.Note that I change 0.25% to 0.25g/100 mL.0.25% w/v is the same as 0.25% g/mL. Dividing by 100% to remove the % we get 0.25g/100 mL.

 Confusing by: HY I thought it is 6pm also, but how come the answer is not there?

 Unsure by: Anonymous I got 10 pm. I'm not sure if that right or not. I multiplied to get total amount of mg in the bag then subtracted from the total desired (750) then, used the rate to determine that it would take 8 hours to get to 750 and since 2pm is 1400 then 8 hrs later would be 10pm