Question

An 89 year old F (62", 59 kg) is admitted to the MICU for hypotension and is started on a Levophed (norepinephrine) drip at 4 mcg/min. The pharmacy technician has prepared a Levophed® IV drip that contains Levophed® 4 mg in NS 250 ml. I. The nurse wants to know at what RATE in ml per hour the IV Levophed® drip should run? Answer: 15 ml/hr II. One day later, you notice that the Levophed® drip as prepared above is infusing at 60 ml/hr. The MD has requested that you adjust the CONCENTRATION of the Levophed® drip to deliver the patient's current dose of Levophed at a rate of 20 ml/hr. How much Levophed should you add to NS 250 ml to prepare this new concentration?

Answer 1

I. Required dosage of levophed is 4 mcg/min.

Amount of levophed administered in one hour = dosage per minute * 60

which is 4 * 60 = 240mcg / hr

IV drip prepared by technician has 4 mg in 250 ml.

that means 4000 mcg in 250 ml

240 mcg is present in 15 ml.

The IV levophed should run at 15ml/hr.

II. The formulation prepared above is being administered at 60ml/hr.

as 15ml/hr contains 240mcg of levophed

60 ml contains 960mcg.

That means 960mcg per hour is the new dosage being administered to the patient.

The MD has requested to adjust the current drug dosage to IV drip of 20ml/hr

That means 960mcg should be given in 20ml preparation.

For 960mcg to be present in 20 ml.

Amount or levophed to be added to 250ml NS is = (drug per 20ml * volume of NS) / 20ml

which is (960*250)/20 = (48*250)

which is 12000 mcg or 12 grams

So, 12 grams of levophed is to be added to 250ml NS to attain present dosage.

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