Tricyclic antidepressants are a class of drugs commonly used for the t
reatment of depression. Tricyclic antidepressants account for approxim
ately 20 Co 25 per cent of drug overdoses that require acute medical a
dmission. The most common cause of mortality is cardiovascular toxicit
y (e,g., arrhythmia, heart block, or hypotension), Other morbidities i
nclude conditions secondary to anticholinergic effects (central and pe
ripheral) and respiratory complications. Ileus, constipation and urina
ry retention are common peripheral anticholinergic sequelae, whereas u
nusual complications include pancreatitis, intestinal pseudo-obstructi
on with cecal perforation, and sigmoid colon gangrene. We report a cas
e of imipramine overdose that was complicated by toxic megacolon with
an associated perforation.