Underdosing of tetracyclic antidepressants, sequela

This code indicates a patient is experiencing a long-term consequence or complication arising from the insufficient administration or intake of a tetracyclic antidepressant medication. This could manifest as a recurrence of the underlying condition the medication was intended to treat, or new symptoms directly attributable to the prolonged under-treatment.

Use this code when documenting a patient's current condition that is a direct result of a past underdosing of a tetracyclic antidepressant. This is appropriate for chronic or residual effects, such as persistent depression or anxiety, that are directly linked to the historical under-administration of the medication. It signifies that the acute underdosing event has passed, but its lasting impact remains.

• Always use this code as a secondary diagnosis, following the code for the specific condition being treated (e.g., major depressive disorder).
• Ensure documentation clearly links the current sequela to a past underdosing event of a tetracyclic antidepressant.
• Do not use for acute underdosing events; this "S" seventh character is specifically for sequelae.