A retrospective analysis of paraquat and diquat poisoning: a single-center experience

Paraquat (PQ) and diquat (DQ) are highly toxic bipyridyl herbicides, but their dominant organ injury patterns and clinical outcomes are not identical. This study aimed to compare the clinical characteristics, organ injury profiles, and prognosis of acute PQ and DQ poisoning.

This retrospective single-center cohort study included consecutive patients with acute oral PQ or DQ poisoning treated at Guangzhou Occupational Disease Prevention and Treatment Hospital between January 2012 and January 2022. Baseline characteristics, clinical manifestations, admission laboratory findings, and in-hospital outcomes were compared between 270 patients with PQ poisoning and 115 patients with DQ poisoning.

PQ poisoning was associated with a higher crude in-hospital mortality rate than DQ poisoning (142/270 [52.6%] vs. 29/115 [25.2%], p < 0.001), shorter hospital stay, higher admission creatinine levels, and more frequent mediastinal emphysema. In contrast, DQ patients were younger, reported larger ingestion amounts, presented later to the local hospital, and more often showed nausea/vomiting, disturbance of consciousness, seizures, reduced responsiveness, agitation, dysarthria, anuria, and pleural effusion. The DQ group also had significantly higher CK and CK-MB levels, suggesting more prominent neuromuscular involvement. Kaplan-Meier analysis showed a significant difference in overall survival between the two groups.

PQ and DQ poisoning show distinct clinical phenotypes and should not be managed as interchangeable toxic syndromes. Rapid toxin identification and toxin-specific monitoring may help guide early risk stratification and supportive care.