The directions for reconstitution of a 500 mg vial of Omnipen (ampicillin sodium) in powder format for injection reads: "Reconstitute with 1.8 mL of sterile water for 500 mg. Each mL of reconstituted solution will contain 250 mg of Omnipen." The patient/client is to receive 500 mg of Omnipen every 6 hours. How many milliliters would the nurse administer?
A) 0.5
B) 1
C) 15
D) 2

Question

Quizplus · Accepted Answer

Refer to directions on the label. The label reads, "Add 1.8 mL sterile water diluent for injection. The resulting solution will contain 250mg/mL of Omnipen." When solving any problem, first check that the order and the supply are in the same weight measure. For this problem, no equivalent is necessary. Estimate the amount to give. Formula Method: 500 mg/250 mg *1 mL = 500/250 = 2 mL. Proportion (Ratios): 1 mL : 250 mg :: x mL : 500 mg; 250x = 500/250 = 2 mL. Proportion (Fractions): 1 mL/250 mg * x mL/500 mg; 250x = 500/250 = 2 mL. Dimensional Analysis: 1 mL/250 mg * 500 mg = 1 mL * 500/250 = 2 mL.

The Directions for Reconstitution of a 500 Mg Vial of Omnipen