The present invention is a pharmaceutical kit for combined parenteral administration, comprising a first formulation containing a first drug, and a second formulation containing a second drug and a parenteral drug delivery system, and it can be used for preventing, reducing or treating an inflammatory reaction of a subject caused by the parenteral drug delivery system of the second formulation, controlling decomposition of the parenteral drug delivery system contained in the second formulation, or increasing bioavailability of the second drug contained in the second formulation.