Examples · Reconstitution
Worked example
Reconstitution - practice problem 6
The prescriber orders 250 mg of ampicillin IV. A 1 g vial directs: add 7.4 mL of diluent to yield 125 mg/mL.
Ordered dose250 mg
Vial1 g
Diluent7.4 mL
After reconstitution125 mg/mL
How many milliliters should the nurse draw up?
Answer: 2 mL
Step-by-step solution
1. Read the concentration after reconstitution
Add 7.4 mL diluent → 125 mg per 1 mL
2. Set up dimensional analysis so mg cancels
250 mg × ( 1 mL ÷ 125 mg )
3. Cancel mg and solve
= 250 ÷ 125 mL
= 2 mL
More reconstitution examples