Late effect of adverse effect of drug, medicinal or biological substance

This code signifies a residual condition or symptom that persists long after the acute adverse reaction to a drug, medicinal, or biological substance has resolved. It describes a lasting health problem directly attributable to a past adverse drug event, rather than the acute event itself.

Use this code when documentation clearly indicates a current condition is a sequela of a previous adverse drug effect. This applies when the original adverse effect is no longer active, but has left a permanent or long-term consequence. Documentation should specify the drug involved and the nature of the late effect.

• Always sequence this code after the code identifying the specific late effect (e.g., chronic kidney disease due to drug toxicity).
• Do not use for acute adverse drug reactions; those require codes from the 995.2x series or specific drug-induced conditions.
• Ensure the medical record explicitly links the current condition to a past adverse drug event, not an ongoing one.