Tricyclic antidepressant (TCA) drugs are also used as adjunctive therapy to treat chronic
pain. To monitor patient compliance to therapy, urine specimens may be preferred since
collection is non-invasive, and the specimen can provide a longer detection window. TCA
drugs are frequently monitored by immunoassay; however, poor antibody specificity may
compromise results. The purpose for this study was to develop a confirmation method for
determining TCA in urine specimens by ultra-pressure liquid chromatography-tandem mass …

To evaluate accuracy, drug-free urine was pooled and used as a matrix to spike 22 samples
with TCA at different concentrations. An additional 33 patient samples were collected and
sent to an alternate laboratory for split sample comparison by gas chromatography-mass
spectrometry (GC/MS). Out of a total of 55 results, there were three false negative results for
nortriptyline and two false negative results for amitriptyline, when compared to compared
GC/MS method. The false negative results could be due to the different sample preparations …