Underdosing of unspecified narcotics, sequela

This code indicates a long-term consequence or complication arising from the patient having previously taken an insufficient amount of an unspecified narcotic substance. It signifies that the underdosing event itself is no longer the acute issue, but its lasting effects are currently being addressed.

Apply this code when a patient presents with a chronic condition, disability, or other persistent health problem directly attributable to a past underdosing of an unspecified narcotic. This is appropriate for follow-up care or management of sequelae, not for the initial underdosing event.

• Requires a seventh character 'S' to denote sequela, indicating the residual effect of a past event.
• Always sequence this code after the code(s) for the specific sequela being treated (e.g., chronic pain, organ damage).
• Do not use for acute underdosing or poisoning; those situations require different seventh characters or codes.