Examples · Reconstitution
Worked example
Reconstitution — practice problem 14
The prescriber orders 400 mg of cefazolin IV. The vial directs: add 5 mL of diluent to yield 200 mg/mL.
Ordered dose400 mg
After reconstitution200 mg/mL
Diluent5 mL
How many milliliters should the nurse draw up?
Answer: 2 mL
Step-by-step solution
1. Read the concentration after reconstitution
Add 5 mL diluent → 200 mg per 1 mL
2. Set up dimensional analysis so mg cancels
400 mg × ( 1 mL ÷ 200 mg )
3. Cancel mg and solve
= 400 ÷ 200 mL
= 2 mL
More reconstitution examples