Adverse effect of drug/meds/biol subst, sequela

This code signifies a long-term or residual condition resulting from a past adverse reaction to a drug, medicament, or biological substance not classified elsewhere. It indicates that the initial adverse effect has resolved, but a permanent or chronic health problem remains as a direct consequence.

Apply this code when documenting a patient's current condition that is a sequela of a previously experienced adverse drug effect. This is appropriate for chronic organ damage, persistent neurological deficits, or other lasting impairments directly attributable to an adverse reaction that occurred in the past.

• Always use this code as a secondary diagnosis, following the code for the specific sequela (e.g., chronic kidney disease, peripheral neuropathy).
• Ensure documentation clearly links the current condition to a prior adverse drug event.
• Do not use this code for acute adverse effects; those require an initial encounter or subsequent encounter code.