Underdosing of emetics, initial encounter

This code signifies that a patient has received an insufficient amount of medication intended to induce vomiting. This underdosing has resulted in a negative clinical outcome or failure to achieve the desired therapeutic effect of emesis.

Apply this code when a patient presents with symptoms of poisoning or overdose, and the administered emetic agent was given in a dose lower than therapeutically indicated, failing to induce vomiting. This would typically be documented in the initial treatment phase of such an event.

• Ensure documentation clearly states that the emetic was underdosed and that this contributed to the patient's condition or treatment failure.
• This "initial encounter" seventh character (A) is used for the period when the patient is receiving active treatment for the underdosing.
• Always code the specific poisoning or adverse effect first, followed by this underdosing code as a secondary diagnosis.