Dosage calculations, until they stop being scary
Problems are generated fresh every time, so there is nothing to memorise and no way to run out. Write the units at every step. That single habit prevents most of the errors this section is designed to catch.
Reconstitution
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A vial of vancomycin contains 500 mg of powder. After reconstitution the final volume is 10 mL. The order is 250 mg IV. How many millilitres will the nurse withdraw?
mL
Round to the nearest tenth.
Formula
Concentration = Total drug ÷ Final volume after reconstitution
Where marks get lost
Using the diluent volume as the final volume. The powder displaces fluid, so read the vial label.