Adverse effect of expectorants, subsequent encounter

This code signifies a patient experiencing an unintended and harmful reaction to an expectorant medication during a follow-up visit. The adverse effect is not due to an overdose or poisoning, but rather a normal therapeutic dose. This could manifest as gastrointestinal upset, rash, or other systemic symptoms.

Use this code when documenting a patient presenting for ongoing management or evaluation of an adverse reaction to an expectorant, such as guaifenesin, after the initial treatment for the adverse effect has begun. This applies to situations where the patient is returning for a check-up related to the adverse effect, or for further treatment of the reaction.

• Always sequence this code after the code for the specific manifestation of the adverse effect (e.g., R21 for rash).
• Ensure documentation clearly states the adverse effect is due to an expectorant and that it's a subsequent encounter.
• Distinguish from initial encounters (A), subsequent encounters (D), and sequela (S) by selecting the appropriate 7th character.