Imipramine overdose complicated by toxic megacolon

Tricyclic antidepressants are a class of drugs commonly used for the treatment of depression. Tricyclic antidepressants account for approximately 20 to 25 per cent of drug overdoses that require acute medical admission. The most common cause of mortality is cardiovascular toxicity (e.g., arrhythmia, heart block, or hypotension). Other morbidities include conditions secondary to anticholinergic effects (central and peripheral) and respiratory complications. Ileus, constipation and urinary retention are common peripheral anticholinergic sequelae, whereas unusual complications include pancreatitis, intestinal pseudo-obstruction with cecal perforation, and sigmoid colon gangrene. We report a case of imipramine overdose that was complicated by toxic megacolon with an associated perforation.