Poisoning by antiviral drugs, undetermined, subs encntr

This code indicates a poisoning event due to an antiviral medication where the intent (e.g., accidental, intentional self-harm, assault) cannot be determined. The patient is receiving active treatment for the effects of the poisoning, or is experiencing sequelae from the initial poisoning event.

Apply this code when documentation clearly states an adverse effect or overdose from an antiviral drug, but the provider cannot ascertain the intent of the exposure. This code is specifically for encounters following the initial treatment phase, such as follow-up appointments for ongoing management of symptoms or complications.

• Requires a fifth character of "D" for subsequent encounter.
• Always sequence this code first for the poisoning, followed by codes for all manifestations.
• Ensure documentation explicitly states "undetermined" intent for antiviral drug poisoning.