Sentence: Toxicological studies revealed that the oral LD50 for thiabendazole in mice was 2200 mg/kg , and when combined with 140 mg/kg of aspirin , the LD50 was reduced to 900 mg/kg .
Drug combination annotation:
[{'class': 'NEG', 'spans': ['thiabendazole', 'aspirin'], 'is_context_needed': False}]