Question

A client is admitted with preeclampsia. A magnesium sulfate infusion is ordered 40 grams in 1,000mL of D5W. The bolus is 4 grams over 30 minutes, followed by a maintenance rate of 0.5 grams/hour. How many mL/hr is the maintenance dose?

Answer 1

Since the maintain end dose ordered is 0.5gm/hr -

and the drug is available as 40gm in 1000ml so ,

1 ml of drug contains - 0.04 gm of drug -

and the asked question is how much drug will be required in ml/ hr for maintenance dose of 0.5gm/hr so ,

1 ml of drug - 0.04 gm

0.5 gm in x ml =

12.5 ml , so the drug required for maintenance dose is 12.5 ml / hr