T43.021Poisoning by tetracyclic antidepressants, accidental (unintentional)

T43.021 is the ICD-10-CM diagnosis code for poisoning by tetracyclic antidepressants, accidental (unintentional). It belongs to category T43 (poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified), block T36-T50 (poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within T43.02 (poisoning by, adverse effect of and underdosing of tetracyclic antidepressants), T43.021 is specifically for poisoning by tetracyclic antidepressants, accidental (unintentional). Related codes cover poisoning by tetracyclic antidepressants, intentional self-harm (T43.022), poisoning by tetracyclic antidepressants, assault (T43.023), poisoning by tetracyclic antidepressants, undetermined (T43.024), adverse effect of tetracyclic antidepressants (T43.025) and underdosing of tetracyclic antidepressants (T43.026).

Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.