Desipramine-induced delirium at "subtherapeutic" concentrations: a case report

An elderly patient treated with low dose Desipramine developed a delirium while her plasma level was in the "subtherapeutic" range. Delirium, which may be induced by tricyclic drug therapy in the elderly, can be caused by tricyclics with low anticholinergic potency. Therapeutic ranges for antidepressants that have been derived from general adult population studies may not be appropriate for the elderly. Further studies of specifically elderly patients are now required to establish safer and more appropriate guidelines for drug therapy.