Poisoning by antiallerg/antiemetic, accidental, init

This code signifies an accidental overdose or adverse reaction to medications primarily used to treat allergies (antihistamines) or prevent/reduce nausea and vomiting (antiemetics). The poisoning is unintentional, meaning the patient did not mean to harm themselves, and it represents the initial phase of treatment for this event.

Apply this code when a patient presents for initial evaluation and treatment following an accidental ingestion of too much diphenhydramine, promethazine, meclizine, or similar drugs. This includes scenarios like a child mistakenly taking an adult's allergy medication or an adult inadvertently taking a double dose.

• Ensure the poisoning is explicitly documented as accidental or unintentional.
• Confirm the drug involved is classified as an antiallergic or antiemetic agent.
• This "initial encounter" code is used for the entire period a patient is receiving active treatment for the poisoning.