Question

Max is a 29 kg collie who needs a Reglan® (metoclopramide) CRI to increase his GI motility. The CRI dose is 2 mg/kg/day. The concentration of Reglan is 5 mg/ml. You have a 1 L bag of normal saline. The fluid rate is 4 ml/kg/hr. How many mLs will be added to his fluids?

Answer 1

Solution:

Take the mass and multiply by the dose

29kg × 2 mg/kg/day (kg cancel out) = 58 mg/day

Now divide by the number of hours in a day (24) to get the per hour rate

(58 mg/day) / (24 hour/day) (day cancel out) = 2.4 mg/hour

Next divide by the concentration of metoclopramide

(2.4 mg/hr) / (5 mg/ml) (mg cancel out) = 0.48 mL metoclopramide/hour

Now find out how many hours this bag will last by taking the amount of fluids in the bag divided by this max current fluid rate:

1000 mL/bag / 4 ml/hr = 250 hours/bag

Lastly, take the number of hours this bag will last and multiply by the mL/hour of metoclopramide:

250 hour/bag × 0.48 mL metaclopramide/hour = 120 mL of metaclopramide/1000 mL bag.

Therefore, 120 mL will be added to his fluids.