Poisoning by antithyroid drugs, accidental, sequela

This code signifies the long-term or residual effects resulting from an accidental overdose or ingestion of antithyroid medications. These sequelae can manifest as persistent thyroid dysfunction (e.g., hypothyroidism or hyperthyroidism), organ damage, or other chronic conditions that developed as a direct consequence of the initial poisoning event. The "sequela" designation indicates that the acute poisoning event has passed, and the patient is now experiencing its lasting impact.

This code is appropriate when a patient presents with a chronic condition or persistent health issue that is documented as a direct result of a past, unintentional poisoning by antithyroid drugs. This would apply to follow-up visits for managing complications such as drug-induced hypothyroidism or liver damage that occurred due to the accidental overdose. It should be used after the acute phase of the poisoning has resolved.

• Always sequence this sequela code after the code(s) for the specific residual condition(s) being treated.
• Ensure documentation clearly links the current condition to a past accidental antithyroid drug poisoning.
• Do not use this code for acute poisoning events; instead, use the appropriate acute poisoning code with the 7th character "A" for initial encounter.