Underdosing of antiasthmatics, initial encounter

This code signifies that a patient has experienced an adverse effect due to taking less than the prescribed or recommended dose of an antiasthmatic medication. This underdosing has led to a new or exacerbated clinical problem, such as an asthma exacerbation, and the patient is receiving initial active treatment for this issue.

Use this code when a patient presents with symptoms or complications directly attributable to not taking enough of their antiasthmatic medication. This applies to situations where the patient is being seen for the first time for this specific underdosing event and its resulting clinical consequences. Examples include a patient admitted to the emergency department for severe asthma due to intentionally or unintentionally missing doses of their inhaler.

• Always assign an additional code for the specific manifestation of the underdosing, such as J45.901 for severe persistent asthma with acute exacerbation.
• Ensure documentation clearly states that the patient took less than the prescribed dose and that this led to the current clinical presentation.
• The "A" seventh character indicates an initial encounter, meaning the patient is receiving active treatment for the underdosing event.