Adverse effect of fentanyl or fentanyl analogs, sequela

This code signifies a long-term or residual condition resulting from a past adverse reaction to fentanyl or its synthetic analogs. It indicates that the acute adverse effect has resolved, but the patient continues to experience a lasting consequence directly attributable to that prior event.

Use this code when documenting a chronic or permanent health problem that is a direct sequela of an adverse effect from fentanyl or fentanyl analogs. This applies to situations where the initial adverse event is no longer active, but its lasting impact is being treated or monitored. Examples include persistent organ damage, neurological deficits, or chronic pain syndromes directly linked to a previous fentanyl adverse reaction.

• Always sequence this sequela code after the code for the specific residual condition being treated.
• Ensure documentation clearly links the current condition as a direct consequence of a past fentanyl adverse effect.
• Do not use this code for acute adverse effects; use the appropriate acute adverse effect code (T40.415A, D) for those scenarios.