TCA poisoning treated in the intensive care unit.

Intoxication with tricyclic antidepressants (TCA) is a common cause of admission to an intensive care unit and a major cause of death due to drug overdose. It is difficult to identify at an early stage those patients for whom toxic events are likely. There is a poor correlation between the plasma concentration of TCAs and the risk of developing toxic symptoms. A better predictor of complications following tricyclic overdose is the level of consciousness on admission to hospital. It has been claimed that "newer" antidepressant agents are less toxic then the classic antidepressants when taken in overdoses. In Sweden, two of these "newer" antidepressants, maprotiline and lofepramine, have been marketed. Of these, only lofepramine is less toxic than the classic TCAs. Maprotiline has the same cardiotoxicity as the TCAs, convulsions are seen more often and a longer plasma half-life leads to longer time spent on a ventilator and longer time in an ICU when it is taken in overdose.