Stability of analgesic admixtures. Degradation and compatibility of common compounds in singular and binary admixtures in use for palliative treatment

Abstract

Analgesic admixtures are given subcutaneously using patient-controlled analgesia devices and are often used in palliative care. The admixtures contain in most cases several compounds to treat multiple conditions. Despite the wide use, there are few data on the physical and chemical stability of the different admixtures. In this preliminary study, we investigated the stability and compatibility of common compounds in singular and binary admixtures diluted in 0.9 % NaCl: morphine, oxycodone, hydromorphone, midazolam and haloperidol in low and high concentrations. All admixtures were prepared aseptically, and the assays were done with HPLC-UV.