Examples · Reconstitution
Worked example
Reconstitution — practice problem 3
The prescriber orders 25 mg of ceftriaxone IV. The vial directs: add 5 mL of diluent to yield 50 mg/mL.
Ordered dose25 mg
After reconstitution50 mg/mL
Diluent5 mL
How many milliliters should the nurse draw up?
Answer: 0.5 mL
Step-by-step solution
1. Read the concentration after reconstitution
Add 5 mL diluent → 50 mg per 1 mL
2. Set up dimensional analysis so mg cancels
25 mg × ( 1 mL ÷ 50 mg )
3. Cancel mg and solve
= 25 ÷ 50 mL
= 0.5 mL
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