T42.8Poisoning by, adverse effect of and underdosing of antiparkinsonism drugs and other central muscle-tone depressants

T42.8 is the ICD-10-CM diagnosis code for poisoning by, adverse effect of and underdosing of antiparkinsonism drugs and other central muscle-tone depressants. 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, choose T42.8 (antiparkinsonism drugs and other central muscle-tone depressants) only when documentation doesn't support a more specific option: hydantoin derivatives (T42.0), iminostilbenes (T42.1), succinimides and oxazolidinediones (T42.2), barbiturates (T42.3), benzodiazepines (T42.4), mixed antiepileptics (T42.5), other antiepileptic and sedative-hypnotic drugs (T42.6) and unspecified antiepileptic and sedative-hypnotic drugs (T42.7).

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.