PHYSICAL COMPATIBILITY OF HIGHLY CONCENTRATED MIDAZOLAM INFUSIONS WITH OTHER DRUGS COMMONLY USED IN INTENSIVE CARE UNITS

Purpose: To determine the physical compatibility of midazolam mixtures with other drugs commonly Y-site administered in intravenous infusion at intensive care units. Method: The drugs studied with midazolam 4 mg/mL were: cisatracurium 2 mg/mL, dobutamine 8 mg/mL, dopamine 8 mg/mL, esomeprazole 0.32 mg/mL, insulin 1 UI/mL, methadone 0.2 mg/mL, noradrenaline 0.32 mg/mL, somatostatin 24 mcg/mL and remifentanil 0.02 mg/mL. The endpoints evaluated were: turbidity, colour change, precipitation and pH. Results: Precipitation and colour change were only observed in the mixture with esomeprazole. Turbidity values were close to 0 NTU (nephelometric turbidity units) in all mixtures, except that of esomeprazole (>40 NTU). The mean pH values were maintained within the stability range of midazolam (3 to 3.6), except in the case of the mixture midazolam-esomeprazole (pH approximate to 4). Conclusions: Midazolam 4 mg/mL is physically compatible, in the reported study conditions, with intravenous (IV) infusions of cisatracurium, dobutamine, dopamine, methadone, noradrenaline, somatostatin and remifentanil, and it is physically incompatible with esomeprazole.