What are the diagnostic criteria for opioid intoxication?
Nov 25, 2025
Source: Cainiu Health
Dr. Wang Lei
Introduction
The diagnosis of opioid intoxication requires a comprehensive assessment based on multiple factors, with core criteria including a clear history of exposure, typical clinical manifestations, specific laboratory tests, exclusion of other diseases, and evaluation of the level of consciousness. In high-risk individuals with a history of substance abuse, relevant examinations should be promptly conducted when suspicious symptoms appear, to establish an early diagnosis and initiate targeted treatment without delay.
Diagnosis of opioid intoxication requires a comprehensive evaluation based on multiple factors. The core criteria include a clear history of exposure, typical clinical manifestations, specific laboratory tests, exclusion of other diseases, and assessment of consciousness. A detailed analysis is as follows:
1. Clear exposure history: It is essential to confirm that the patient has been exposed to opioids such as heroin, morphine, or pethidine. Detailed information regarding the route, dosage, and timing of exposure should be obtained. Some patients may have a history of long-term abuse or recent dose escalation—such details form the foundation for diagnosis.
2. Typical clinical manifestations: Classic triad symptoms following intoxication include respiratory depression, miosis (pinpoint pupils), and coma. Additional signs may include cold and clammy skin, hypotension, bradycardia, nausea, and vomiting. The severity of symptoms typically correlates with the dose of opioid exposure.
3. Specific laboratory tests: Detection of opioids and their metabolites in blood or urine is crucial for definitive diagnosis, commonly performed using immunoassays or chromatographic methods. Arterial blood gas analysis should also be conducted to identify potential respiratory failure or acid-base imbalances, which guide treatment decisions.
4. Exclusion of other conditions: Differential diagnosis must rule out sedative-hypnotic drug poisoning, stroke, hypoglycemic coma, and similar conditions. Sedative-hypnotic poisoning does not present with pinpoint pupils; stroke often presents with focal neurological deficits such as hemiplegia; hypoglycemic coma can be rapidly differentiated by blood glucose testing. Only after excluding these conditions can a definitive diagnosis of opioid intoxication be established.
5. Assessment of consciousness: The Glasgow Coma Scale (GCS) is used to evaluate the level of consciousness. Patients with opioid intoxication often present with drowsiness, stupor, or coma, with GCS scores decreasing as intoxication worsens. Changes in consciousness reflect the severity of poisoning and serve as an important indicator for monitoring treatment response.
In the diagnostic process, all criteria should be integrated to avoid misdiagnosis due to reliance on a single factor. For high-risk individuals with a history of substance abuse, prompt evaluation and relevant testing should be initiated when suggestive symptoms appear, enabling early diagnosis and timely initiation of targeted therapy.
