TCA (Tricyclic Antidepressants) are commonly used for the treatment of depressive disorders. TCA overdoses can result in profound central nervous system depression, cardiotoxicity and anticholinergic effects. TCA overdose is the most common cause of death from prescription drugs. The TCA One Step Tricyclic Antideperssants Test Strip (Urine) is a rapid chromatographic urine-screening test that can be performed without the use of an instrument. The test utilizes a monoclonal antibody to selectively detect elevated levels of nortriptyline in urine. It yields a positive result when the Nortriptyline in urine exceeds 1,000 ng/mL.