Underdosing of antithrombotic drugs, sequela

This code signifies a patient's long-term health consequences or complications arising from the insufficient administration or intake of antithrombotic medications. These drugs are crucial for preventing blood clot formation. The underdosing has led to persistent or residual effects that are still present after the acute phase of the underdosing event.

Use this code when documenting conditions such as chronic deep vein thrombosis (DVT), pulmonary embolism (PE), or recurrent strokes that are directly attributed to a historical period of inadequate antithrombotic therapy. This applies when the patient is no longer acutely underdosed, but the sequelae of that underdosing are being treated or monitored. This code is appropriate for follow-up visits addressing these long-term complications.

• Always use this code as a secondary diagnosis, following the code for the specific sequela (e.g., I26.01 for pulmonary embolism with acute cor pulmonale).
• Ensure documentation clearly links the current condition to a past underdosing event, specifying the antithrombotic drug class if possible.
• The "S" in the seventh character indicates sequela, meaning the residual effects of the underdosing are being treated. Do not use for acute underdosing.