Therapeutic monitoring of benzodiazepines in the management of pain: Current limitations of point of care immunoassays suggest testing by mass spectrometry to assure accuracy and improve patient safety

► Point of care tests gave 20% false negative results for benzodiazepines. ► The devices often failed to produce positive results for lorazepam or clonazepam. ► Seventy three out of 498 patients were positive for two or more benzodiazepines.