CrossDDI: Cross-Source Evidence-Grounded Drug-Drug Interaction Verification

Bohao Chu, Norbert Fuhr


Abstract
LLM-based drug–drug interaction (DDI) assessment remains difficult to audit when predictions are not explicitly tied to evidence. While retrieval-augmented generation (RAG) improves grounding, predictions are not guaranteed to be entailed by retrieved items. We present CrossDDI, a verification-first framework that separates LLM-based evidence extraction from deterministic, LLM-free arbitration over DrugBank and PubMed, requiring positive predictions to be linked to explicit supporting evidence. Evaluated on 1,000 DDInter 2.0 pairs under a positive–unlabeled setting, CrossDDI achieves recall of 0.576–0.593 over confirmed positives with interaction prediction rates comparable to RAG, while reducing cross-backbone variation (0.018 vs. 0.066). Analysis identifies literature evidence acquisition and attribution as the primary bottleneck: PubMed retrieval covers only 40.5% of confirmed positives, and Path B-only evidence is substantially less reliable than structured evidence. These results suggest that verification-first architectures can improve traceability and backbone consistency, while broader and more reliable literature evidence is needed to extend coverage beyond structured sources.
Anthology ID:
2026.bionlp-1.73
Volume:
BioNLP 2026
Month:
July
Year:
2026
Address:
San Diego, California
Editors:
Dina Demner-Fushman, Sophia Ananiadou, Kirk Roberts, Junichi Tsujii
Venues:
BioNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
911–919
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-1.73/
DOI:
Bibkey:
Cite (ACL):
Bohao Chu and Norbert Fuhr. 2026. CrossDDI: Cross-Source Evidence-Grounded Drug-Drug Interaction Verification. In BioNLP 2026, pages 911–919, San Diego, California. Association for Computational Linguistics.
Cite (Informal):
CrossDDI: Cross-Source Evidence-Grounded Drug-Drug Interaction Verification (Chu & Fuhr, BioNLP 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-1.73.pdf