Adverse effect of unsp systemic antibiotic, init encntr

This code signifies an undesirable or harmful reaction experienced by a patient due to the therapeutic use of a systemic antibiotic, where the specific antibiotic agent is not documented. This adverse effect occurred during the initial phase of treatment or the first time the patient presented for this specific condition.

Apply this code when a patient presents with symptoms clearly linked to an adverse reaction from an antibiotic, but the medical record does not specify which antibiotic caused the reaction. This is appropriate for initial encounters where the adverse effect is being evaluated or treated for the first time.

• Always sequence this code after the code for the specific manifestation of the adverse effect (e.g., rash, anaphylaxis).
• Avoid using this code if the specific antibiotic is known; instead, use the more specific T36.0-T36.8 series.
• Ensure documentation clearly states an "adverse effect" and not poisoning, underdosing, or an allergic reaction if the specific allergen is known.