Poisoning by unspecified drug or medicinal substance

This code signifies an adverse health effect resulting from an overdose or toxic reaction to a drug or medicinal substance where the specific agent involved is unknown or not documented. It indicates a poisoning event without identifying the particular pharmaceutical or chemical causing the harm.

Use this code when a patient presents with symptoms of poisoning, and medical documentation clearly states a drug or medicinal substance is the causative agent, but the specific drug or substance cannot be identified. This is often applicable in emergency department settings where immediate identification of the toxic agent is not possible, or when the patient is unable to provide a history and no other information is available.

• Avoid using this code if any specific drug or medicinal substance is identified; instead, code to the specific substance.
• Always sequence this code as a principal diagnosis when it is the reason for the encounter, followed by codes for manifestations of the poisoning.
• Review documentation carefully for any clues, even vague ones (e.g., "opioid overdose," "sedative poisoning"), that would allow for a more specific poisoning code.