Question

Ordered: rocephin 500 mg IM bid. available: rocephin 0.5 g vial.

directions: add 1.8 mL of diluent to yield 250 mg/mL. Add 1 mL of
diluent to yield 350 mg/mL. How many mL will you give if you add 1
mL

Answer 1

After reconstituting a 0.5 g vial of Rocephin (ceftriaxone) with 1 mL of diluent to achieve a concentration of 350 mg/mL, administer 1.43 mL to deliver the ordered dose of 500 mg.

Step-by-step explanation:

The question asks about the calculation for the administration of a dose of Rocephin (ceftriaxone) based on its concentration after reconstitution. Given the directions for reconstitution and the ordered dose, the calculation will determine the volume of medication to administer.

If we reconstitute the 0.5 g vial of Rocephin with 1 mL of diluent to achieve a concentration of 350 mg/mL, and the ordered dose is 500 mg IM bid (twice daily), the volume to administer for each dose is calculated as follows:

Dose (mg) / Concentration (mg/mL) = Volume (mL) to Administer

500 mg / 350 mg/mL = 1.43 mL

Therefore, 1.43 mL of the reconstituted medication should be administered to deliver the ordered dose of 500 mg.