Poisoning by antithyroid drugs, undetermined, sequela

This code signifies a long-term or residual effect resulting from a poisoning event involving antithyroid medications, where the intent of the poisoning (accidental, intentional self-harm, assault) cannot be determined. The patient is no longer in the acute phase of the poisoning but is experiencing ongoing health issues directly attributable to the past exposure to these drugs.

Apply this code when documenting a patient presenting with chronic or persistent symptoms, conditions, or complications that are a direct consequence of a previous antithyroid drug poisoning, and the circumstances surrounding the original poisoning remain unknown. This is appropriate for follow-up encounters after the acute poisoning has resolved, but its lasting impact is still being managed.

• Always sequence this sequela code after the code for the specific manifestation of the sequela (e.g., a specific endocrine disorder).
• Ensure documentation clearly links the current condition to a past antithyroid drug poisoning with undetermined intent.
• Do not use this code for acute poisoning events; instead, use the appropriate acute poisoning code with the 7th character for initial, subsequent, or sequela encounter.