This paper addresses the serious global health problem of drug overdose due to the misuse of opioids, analgesics, and psychiatric drugs. To overcome the limitations of existing research methods, we utilize real-time reported drug use and overdose symptom information from social media. The main content is to propose an AI-based NLP framework based on social media data, and to apply traditional ML models, neural networks, and advanced transformer-based models to detect drug and related overdose symptoms through a hybrid annotation strategy using LLM and human annotators. As a result, we achieve 98% accuracy in multi-class classification and 97% in multi-label classification, which is up to 8% better performance than the baseline model. This demonstrates the potential of AI to support public health surveillance and personalized intervention strategies.