The compatibility and stability of midazolam and dexamethasone in infusion solutions

The delivery of subcutaneous medication by continuous infusion is common in palliative medicine. Many centers combine multiple medications, but the analytical confirmation of the compatibility and stability of these combinations has rarely been performed. This study examined the compatibility and stability of midazolam and dexamethasone using high performance liquid chromatography. Nine different solutions were prepared in polypropylene syringes by combining these two drugs with 0.9% sodium chloride. Men these two drugs were combined in a syringe, there was significant loss of midazolam over 48 hours, with only 60-80% of the initial concentration remaining in syringes stored at 35-39degreesC. This study demonstrates that cloudiness of a solution is not the only Predictor of drug loss and that drug loss may Occur even in solutions that remain clear at time of preparation. The clinical implications of these results are that dexamethasone and midazolam should not be combined in syringe driver solutions. (C) 2004 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.