T42.3Poisoning by, adverse effect of and underdosing of barbiturates

T42.3 is the ICD-10-CM diagnosis code for poisoning by, adverse effect of and underdosing of barbiturates. It belongs to category T42 (poisoning by, adverse effect of and underdosing of antiepileptic, sedative- hypnotic and antiparkinsonism drugs), 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 1 subcodes must be used instead.

Within T42 (poisoning by, adverse effect of and underdosing of antiepileptic, sedative- hypnotic and antiparkinsonism drugs), T42.3 is specifically for poisoning by, adverse effect of and underdosing of barbiturates. Related codes cover hydantoin derivatives (T42.0), iminostilbenes (T42.1), succinimides and oxazolidinediones (T42.2), benzodiazepines (T42.4), mixed antiepileptics (T42.5), other antiepileptic and sedative-hypnotic drugs (T42.6), unspecified antiepileptic and sedative-hypnotic drugs (T42.7) and antiparkinsonism drugs and other central muscle-tone depressants (T42.8).

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.

Don't report T42.3 together with the conditions in its Excludes1 note: poisoning by, adverse effect of and underdosing of thiobarbiturates (T41.1-).

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