Poisoning by unspecified drug primarily affecting autonomic nervous system

This code signifies an adverse reaction or overdose from an unknown pharmaceutical agent that primarily manifests with symptoms related to the autonomic nervous system. These symptoms might include disturbances in heart rate, blood pressure, digestion, or pupillary function.

Apply this code when documentation clearly indicates a poisoning event with autonomic nervous system effects, but the specific drug responsible cannot be identified. This is often used in emergency department settings or when a patient presents with altered mental status and a history of drug exposure, but toxicology screens are pending or inconclusive.

• Always attempt to identify the specific drug involved; this code is for unspecified agents only.
• Code any specific autonomic nervous system manifestations (e.g., tachycardia, bradycardia) as additional diagnoses.
• Ensure documentation supports the "unspecified" nature of the drug, such as "unknown substance" or "drug not identified."