Underdosing of antineoplastic and immunosup drugs, init

This code signifies that a patient has intentionally or unintentionally taken less than the prescribed amount of medication designed to treat cancer or suppress the immune system. This underdosing can lead to suboptimal therapeutic effects, disease progression, or treatment failure. It is distinct from adverse effects or poisoning.

Apply this code when documentation clearly indicates a patient received or self-administered an insufficient dose of an antineoplastic or immunosuppressant drug. This includes situations where the patient missed doses, took partial doses, or the prescribed dose was inadequate for the intended therapeutic effect. This specific code is for the initial phase of treatment for this underdosing event.

• Always sequence this code after the code(s) for the condition being treated by the underdosed medication.
• Ensure documentation specifies "underdosing" and identifies the drug class (antineoplastic or immunosuppressive).
• Verify the encounter type is "initial" for this specific underdosing event; subsequent encounters would use different seventh characters.