need explanation for this math concept - pl. help.

[ydom]

You are told to prepare a double strength Dopamine IV drip because a patient is requiring large doses to obtain the drug’s effects.
The usual Dopamine drip concentration is 400 mg in 250 ml. The patient weighs 176 pounds and needs the pressor dose level of
dopamine (10 mcg/kg/min). Dopamine Injection is available as 40 mg per mL in 10 mL vials.
Answer the following questions:


How many mL of the 40 mg per mL Dopamine Injection should be added to a 500 mg bag of IV
fluid to prepare the double concentration? (Ignore volume of the dopamine injection.)

pl. explain concept of double strength
thanks

[3boooda]

Double strength means 800 mg per 250 cc.

[fpgeepharma]

833ml?

[3boooda]

833ml?

No it would be 20 ml

[ydom]

yes you are right 3booda....20 ml is required. (oh,sorry, correction in question --- It is not 500 mg bag required, but 500 ml bag that is required)

[Moora]

How can it be 20mls??? For double strength it should be 40mls...

This is how I worked it out... For double strength it is 800mg per 250mls... so it is 1600mg in 500mls...

If a 1 ml in vial has 40 mg
then x mls will have 1600mg

so x= 1600/40= 40mls is required to be injected in 500ml in IV bag....