Adverse effect of thyroid hormones and substitutes, subs

This code signifies a patient experiencing an unintended and undesirable reaction to thyroid hormones or their synthetic substitutes during a follow-up visit. These adverse effects can range from mild symptoms like palpitations or anxiety to more severe complications such as cardiac arrhythmias or osteoporosis, resulting from either over- or under-dosing, or an idiosyncratic reaction.

Assign this code when a patient presents for ongoing management or evaluation of an adverse effect from thyroid hormone medication (e.g., levothyroxine, liothyronine) after the initial treatment for the adverse effect has already begun. This typically applies to follow-up appointments where the patient's condition related to the adverse effect is being monitored, adjusted, or further investigated.

• Ensure the documentation clearly states the encounter is for a subsequent evaluation or management of the adverse effect.
• Always code the specific manifestation of the adverse effect (e.g., R00.2 for palpitations) as a primary or secondary diagnosis.
• Do not use this code for initial encounters for the adverse effect; a different 7th character would be appropriate.