2025 ICD-10-CM code T50.9
Poisoning by, adverse effect of and underdosing of other and unspecified drugs, medicaments and biological substances
Medical necessity is established by the clinical presentation of the patient. The documentation should support the diagnosis of poisoning, adverse effect, or underdosing, and the need for medical intervention.
The clinician is responsible for documenting the specific drug, medication, or biological substance involved, the route of exposure, the circumstances of the event, and the signs and symptoms observed.If the event was unintentional, intentional self-harm, assault, or undetermined, this should be clearly documented.It is also important to document the response to any treatment provided.
In simple words: This code is used when someone has been poisoned by, had a bad reaction to, or has taken too little of a drug, medication, or biological substance, excluding common drugs like narcotics or those specifically listed elsewhere in the code set.
Poisoning by, adverse effect of and underdosing of other and unspecified drugs, medicaments and biological substances. This code includes adverse effects of correctly administered substances, poisoning by overdose, poisoning by the wrong substance given or taken in error, and underdosing.
Example 1: A patient presents to the emergency room after accidentally ingesting a bottle of unmarked pills found in their grandparent's medicine cabinet. The pills are later identified as a dietary supplement. The patient experiences nausea and dizziness., A patient is admitted to the hospital after intentionally overdosing on an over-the-counter sleep aid. The patient exhibits lethargy, confusion, and respiratory depression., A patient is prescribed a new medication for anxiety. They experience severe hives and itching, indicative of an allergic reaction.
Documentation should include the name of the drug, medication, or biological substance if known, the route of exposure (ingestion, injection, inhalation, etc.), the amount or dose if known, the time of exposure or ingestion, the clinical signs and symptoms, and any treatment provided. It should also include information about whether the incident was accidental, intentional, or of undetermined intent.
** For adverse effects, code first the nature of the adverse effect, such as: adverse effect NOS (T88.7), aspirin gastritis (K29.-), blood disorders (D56-D76), contact dermatitis (L23-L25), dermatitis due to substances taken internally (L27.-), nephropathy (N14.0-N14.2). The drug giving rise to the adverse effect should be identified by using codes from categories T36-T50 with the fifth or sixth character 5. Use additional code(s) to specify manifestations of poisoning, underdosing, or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9) and underdosing of medication regimen (Z91.12-, Z91.13-).
- Payment Status: Active
- Specialties:Emergency medicine, Internal medicine, Toxicology, Pediatrics, Family medicine
- Place of Service:Emergency Room - Hospital, Inpatient Hospital, Office, Home, Other Place of Service