Adverse effect of antineoplastic and immunosup drugs, subs

This code signifies a harmful or undesirable reaction experienced by a patient due to the therapeutic use of antineoplastic (chemotherapy) or immunosuppressive medications. The adverse effect is being managed or monitored during a follow-up visit, after the initial treatment for the reaction has already begun.

Apply this code when a patient presents for ongoing management, evaluation, or monitoring of an adverse effect from antineoplastic or immunosuppressive drugs. This includes situations where the patient is receiving further treatment for the reaction, or the provider is assessing the effectiveness of previous interventions. It is appropriate for encounters following the initial diagnosis and treatment of the adverse effect.

• Always sequence the specific adverse effect (e.g., anemia, neuropathy) as the primary diagnosis, followed by this code.
• Ensure the documentation clearly indicates that the encounter is for follow-up care of the adverse effect, not the initial presentation.
• Distinguish from poisoning (T36-T50 with 1-4th character 1-4) which implies an accidental overdose, wrong drug, or non-therapeutic intent.