Underdosing of tricyclic antidepressants, sequela

This code indicates that a patient has experienced a long-term or residual effect due to receiving an insufficient amount of tricyclic antidepressant medication. This underdosing could lead to a recurrence or worsening of the underlying condition the medication was intended to treat, or other adverse health consequences.

Use this code when documenting a patient's current health problem that is a direct result of a past or ongoing underdosing of a tricyclic antidepressant. This is appropriate for conditions like persistent depression or anxiety that are attributed to inadequate medication levels, even after the underdosing itself may have been corrected.

• Always use this code as a secondary diagnosis, following the code for the specific sequela (e.g., recurrent major depressive disorder).
• Ensure documentation clearly links the current condition to the historical or chronic underdosing of the tricyclic antidepressant.
• The "S" in the 7th character indicates sequela, meaning it's for conditions that are the late effects of the underdosing.