From Free-text Drug Labels to Structured Medication Terminology with BERT and GPT.

We present a method to enrich controlled medication terminology from free-text drug labels. This is important because, while controlled medication terminology capture well-structured medication information, much of the information pertaining to medications is still found in free-text. First, we compared different Named Entity Recognition (NER) models including rule-based, feature-based, deep learning-based models with Transformers as well as ChatGPT, few-shot and fine-tuned GPT-3 to find the most suitable model that accurately extracts medication entities (ingredients, brand, dose, etc.) from free-text. Then, a rule-based Relation Extraction algorithm transforms NER results into a well-structured medication knowledge graph. Finally, a Medication Searching method takes the knowledge graph and matches it to relevant medications in the terminology server. An empirical evaluation on real-world drug labels shows that BERT-CRF was the most effective NER model with F-measure 95%. After performing terms normalization, the Medication Searching achieved an accuracy of 77% for when matching a label to relevant medication in the terminology server. The NER and Medication Searching models could be deployed as a web service capable of accepting free-text queries and returning structured medication information; thus providing a useful means of better managing medications information found in different health systems.