Compatibility of etoposide phosphate with selected drugs during simulated Y-site injection

To evaluate the physical compatibility of etoposide phosphate with 101 selected secondary drugs, including antineoplastic chemotherapy agents, anti-infectives, and supportive care drugs, during simulated Y-site injection.

Five-milliliter samples of etoposide 5 mg/mL as phosphate in 5% dextrose injection were mixed with 5 mL of the selected drugs diluted in 5% dextrose injection or, if necessary to avoid incompatibilities with the diluent, 0.9% sodium chloride injection. Samples were examined visually in normal fluorescent light with the unaided eye and using a Tyndall beam (high-intensity monodirectional light) to enhance the visibility of small particles and low-level haze. Turbidity of each sample was measured. In selected samples, electronic particle content assessment was performed. All of the samples were assessed initially and at one and four hours.

Most of the secondary drugs were physically compatible with etoposide phosphate during the four-hour observation period. However, seven drug combinations had incompatibilities that included color change, increase in haze or turbidity, particulate formation, and gross precipitation. The drugs that were observed to be physically incompatible with etoposide phosphate were amphotericin B, cefepime hydrochloride, chlorpromazine hydrochloride, imipenem-cilastatin sodium, methylprednisolone sodium succinate, mitomycin, and prochlorperazine edisylate.

Etoposide 5 mg/mL as phosphate in 5% dextrose injection is physically compatible for four hours at room temperature during simulated Y-site administration with 94 of the 101 drugs selected. Simultaneous Y-site administration of etoposide phosphate with the seven incompatible drugs should be avoided.