False-positive drug test results in patients taking psychotropic drugs. A literature review.

INTRODUCTION

The study reviews the literature on false-positive drug test results in patients taking psychotropic medications.

METHOD: A narrative review of available literature in English and Polish was conducted by searching MEDLINE/PubMed and Google Scholar databases using the search phrase ‛falsepositive drug test' and names of selected registered antidepressant, antipsychotic and mood stabilizing medications as well as pharmaceuticals used in the treatment of ADHD. Review articles, case reports and original papers from years 1990-2019 were analyzed.

RESULTS

False-positive drug test results have been reported for many psychiatric drugs: clomipramine, amitriptyline, bupropion, trazodone, sertraline, venlafaxine, hydroxyzine, haloperidol, sulpiride, perazine, levomepromazine, aripiprazole, risperidone, amisulpride, quetiapine, lamotrigine, carbamazepine, methylphenidate, and atomoxetine. No such reports have been found for other drugs considered in this study.

CONCLUSIONS

When interpreting urine drug tests, caution should be exercised, especially when the tested person categorically denies the use of psychoactive substances. In such situations, the patient's medication list should be analyzed to ascertain that the obtained result is not false-positive. When test results are unclear, the presence of drugs in the urine can be effectively confirmed or excluded using gas chromatography. Unfortunately, most of the data available in the literature are case reports, which means they require further support from studies of large cohorts of patients taking psychotropic medications.