Underdosing of tricyclic antidepressants, initial encounter

This diagnosis code signifies a patient presenting with adverse effects or complications due to taking less than the prescribed or recommended dose of a tricyclic antidepressant. This underdosing can lead to a lack of therapeutic effect or worsening of the underlying condition for which the medication was prescribed.

Apply this code when documentation clearly indicates that a patient's current symptoms or condition are a direct result of not taking enough tricyclic antidepressant medication. This is appropriate for the initial visit where the underdosing is identified and treated.

• Always confirm the specific drug class (tricyclic antidepressant) is documented.
• Ensure the encounter is the "initial encounter" for the underdosing event. Subsequent encounters would use a different seventh character.
• Code any resulting adverse effects or symptoms separately, in addition to this underdosing code.