Tricyclic antidepressants (TCAs) are a class of medications formerly widely prescribed for the treatment of depression. Analysis for these substances is frequently included in drug testing panels for a variety of reasons, including monitoring adherence to prescribed medication, detecting potential misuse, and identifying possible causes of impaired mental status. When such an analysis is performed, the test is designed to detect the presence of the parent drug and/or its metabolites in a biological sample, typically urine or blood.
The presence of TCAs may be relevant in several contexts. In clinical settings, it can verify that a patient is taking their prescribed medication as directed. In forensic settings, the detection of these substances can be relevant in cases involving driving under the influence or investigations into overdose. Furthermore, because TCAs can have significant side effects, including cardiac arrhythmias, their presence in a drug screen may prompt further investigation to ensure patient safety.