Application of the CEDIA 6-MAM assay to routine drugs-of-abuse screening

A total of 1010 urine specimens obtained from General Practitioners, drug dependency units, and hospitals throughout the West Midlands were screened using the Microgenics CEDIA 6-monoacetylmorphine (6-MAM) assay as a means of establishing its effectiveness as a screening technique to monitor heroin abuse. A total of 282 specimens screened positive for 6-MAM using the CEDIA 6-MAM assay. However, the presence of 6-MAM could not be confirmed by gas chromatography-mass spectrometry in 21 (7%) of the CEDIA-positive specimens. Morphine was identified in all of these specimens at free concentrations ranging between 410 microg/L to 2010 microg/L. The data presented from this preliminary investigation suggests that either there are substances present within the urine specimens, as yet undetermined, which are interfering with the assay or that there may be a greater degree of cross reactivity to other opiates than previously published. 6-MAM assays may be potentially useful rapid screening techniques for high-throughput drugs-of-abuse screening laboratories performing employment and pre-employment screening. However, all positive results will still need to be confirmed by a more sensitive and specific technique.