Tricyclic antidepressants (TCAs) are a group of drugs that contain a characteristic three ringed nucleus structure. They have been used in the treatment of various forms of depression, anxiety disorders, attention deficit hyperactivity disorder and enuresis in children and as an adjunct to analgesics for certain chronic and neuropathic pain syndromes. Whilst therapeutic drug monitoring (TDM) of TCA's is well established in the treatment of depression, TCA overdose remains the most common cause of death from prescription drugs(1, 2).