Adverse effect of unsp prim sys and hematolog agent, sequela

This code signifies a lasting or residual condition resulting from an adverse reaction to a systemic or hematological medication where the specific agent is unknown. The patient experienced an undesirable effect from a drug, and the current encounter is for the management of a chronic or permanent sequela directly attributed to that past adverse event.

Apply this code when a patient presents with a long-term complication or permanent damage due to an adverse drug reaction from an unidentifiable systemic or hematological agent. This is appropriate for follow-up care of conditions like persistent organ damage, chronic neurological deficits, or ongoing hematological abnormalities that are directly linked to a past, unspecified drug-induced event. The "S" seventh character indicates that this is a sequela, meaning the acute phase of the adverse effect has passed.

• Always sequence this code after the code(s) for the specific sequela being treated.
• Use this code only when the specific drug causing the adverse effect cannot be identified or documented.
• Ensure documentation clearly links the current sequela to a past adverse drug event.