Stability of flumazenil with selected drugs in 5% dextrose injection

The compatibility and stability of flumazenil mixed with aminophylline, dobutamine hydrochloride, dopamine hydrochloride, cimetidine hydrochloride, famotidine, ranitidine hydrochloride, heparin sodium, lidocaine hydrochloride, or procainamide hydrochloride were studied. Flumazenil (1.0 mg) was mixed with each of the other drugs in polyvinyl chloride minibags containing 50 mL of 5% dextrose injection to achieve concentrations commonly used when the drugs are administered by continuous i.v. infusion. All admixtures were analyzed for color change, pH, and particulate matter. Flumazenil concentrations were measured by a stability-indicating high- performance liquid chromatographic assay at baseline and 2, 4, 8, 12, and 24 hours after mixing. No detectable changes in color, pH, or particulate matter were observed. In the presence of each drug except dopamine hydrochloride, at least 95% of initial flumazenil concentration was present 24 hours after mixing. Flumazenil in the presence of dopamine hydrochloride was stable for 12 hours. Flumazenil was visually compatible and chemically stable when admixed with 5% dextrose injection and selected drugs.