2-Methyl-4-chlorophenoxyacetic acid (MCPA) and bromoxynil herbicide ingestion. (4th May 2018)

• Record Type: Journal Article
• Authors: Chiew, Angela L.; Page, Colin B.; Clancy, David; Mostafa, Ahmed; Roberts, Michael S.; Isbister, Geoffrey K.
• Is Part Of: Clinical toxicology. Volume 56:Number 5(2018)
• Page Start: 377
• Page End: 380
• Publication Date: 2018-05-04
• Subjects: Herbicide -- overdose -- poisoning -- extracorporeal elimination; Toxicology -- Periodicals; Toxicological emergencies -- Periodicals; 615.9
• DOI: 10.1080/15563650.2017.1385790
• Languages: English
• ISSNs: 1556-3650

Abstract

Abstract: Context: Ingestion of bromoxynil and 2-methyl-4-chlorophenoxyacetic acid (MCPA) in combination is associated with high mortality. Toxicity is characterised by hyperthermia and metabolic acidosis. Dialysis is a proposed treatment, but little data exist regarding its effectiveness. Case details: Case 1: A 50-year-old female presented 18 h post-ingestion of 200 mL of bromoxynil(200 g/L) and MCPA(200 g/L). She was agitated, tachycardic and tachypnoeic. She was intubated and continuous venovenous haemodiafiltration (CVVHDF) was commenced. She deteriorated, becoming hypotensive, hyperthermic (39.5 °C) and hypercapnic (80 mmHg). She was cooled, paralysed, received CVVHDF for 2d and was extubated on day 4 making a full recovery. Case 2: A 60-year-old male presented 6 h post-ingestion of an unknown amount of bromoxynil (200 g/L) and MCPA (200 g/L). On arrival, he was tachycardic and tachypneic (pCO2 25 mmHg). At 8h post-ingestion he became hyperthermic, hypercapnic and acidotic (pH 7.15), and was intubated, paralysed, cooled and received CVVHDF for 36 h. He was extubated after 42 h and made a full recovery. Bromoxynil and MCPA serum and effluent concentrations were measured. Peak MCPA serum concentrations were 161 µg/ml and 259 µg/ml and peak bromoxynil concentrations were 119 µg/ml and 155 µg/ml in case 1 and 2, respectively. The estimated clearance of both herbicides by CVVHDF was low (<10 mL/min). Conclusion: CVVHDF did not result in significant clearance of either herbicide but may have assisted with hyperthermia control. Both patients survived with vigorous cooling, paralysis and ventilatory support.