Adverse effect of antithyroid drugs, initial encounter

This code signifies a patient experiencing an unintended and harmful reaction to medication specifically prescribed to treat an overactive thyroid gland. The adverse effect is occurring for the first time or is an acute exacerbation of an existing condition.

Apply this code when documenting conditions such as agranulocytosis, liver dysfunction, rash, or arthralgia directly attributable to antithyroid medications like methimazole or propylthiouracil. This is appropriate for the initial assessment and treatment of the adverse reaction.

• Always sequence this code after the code for the specific manifestation of the adverse effect.
• Ensure documentation clearly links the adverse reaction to the antithyroid drug.
• Do not use this code for poisoning, underdosing, or therapeutic drug use without an adverse effect.