Underdosing of unspecified systemic antibiotic, init encntr

This code signifies that a patient has not taken an unspecified systemic antibiotic as prescribed, resulting in a suboptimal or insufficient dose. This underdosing can lead to treatment failure, prolonged illness, or the development of antibiotic resistance.

Use this code when documentation indicates a patient's non-adherence to an antibiotic regimen, but the specific antibiotic is not identified. This often occurs when a patient self-reports not taking their medication as directed, or when a healthcare provider suspects underdosing without knowing the exact drug.

• Ensure the documentation clearly states "underdosing" and that the antibiotic is systemic and unspecified.
• The "XA" seventh character indicates an initial encounter for this underdosing event.
• Always look for more specific codes if the type of antibiotic is known (e.g., penicillin, macrolide).