Underdosing of antiallergic and antiemetic drugs, init

This code signifies that a patient has taken less than the prescribed amount of medication intended to treat allergies or prevent vomiting. This underdosing has led to a negative health consequence or is being investigated as a potential cause for the patient's current symptoms.

Apply this code when a patient presents with persistent allergic reactions or uncontrolled nausea/vomiting because they did not take enough of their antiallergic or antiemetic medication. This is also appropriate for the initial visit where the underdosing is identified or first addressed.

• Always assign an additional code for the specific adverse effect or condition resulting from the underdosing.
• Ensure documentation clearly states the patient's non-compliance with the prescribed dosage.
• This "A" seventh character indicates an initial encounter for the underdosing event.