Adverse effect of phenothiazine antipsychot/neurolept, subs

This code signifies a harmful or undesirable reaction to a phenothiazine antipsychotic or neuroleptic medication that is being addressed during a follow-up visit. The patient is experiencing an adverse effect, not an accidental poisoning or underdosing, from a medication prescribed and administered correctly.

Apply this code when a patient presents for ongoing management or evaluation of an adverse effect caused by a phenothiazine antipsychotic or neuroleptic, such as tardive dyskinesia, akathisia, or neuroleptic malignant syndrome, after the initial treatment for the adverse effect has begun. This code is appropriate for subsequent encounters related to the adverse effect.

• Always sequence this code after the code for the specific adverse effect (e.g., G24.0 for drug-induced tardive dyskinesia).
• Ensure documentation clearly states the adverse effect is due to a phenothiazine antipsychotic or neuroleptic.
• Differentiate from poisoning (T43.3X1-) or underdosing (T43.3X6-), which have different code assignments.