Imidacloprid poisoning case series: potential for liver injury

Abstract

Introduction: Imidacloprid is a commonly used neonicotinoid insecticide in Thailand. Limited reports suggest it may be associated with liver injury.

Case series: A retrospective poison center case series identified 128 cases of imidacloprid ingestion from 2010–2016, of which four developed liver injury.

Results: Three patients ingested soluble liquid concentrates and one ingested water-dispersible granules of imidacloprid. The estimated doses of ingestion ranged from 2–35 g. One patient developed cholestatic liver injury, two developed hepatocellular liver injury, and the remaining patient, who ingested the highest dose, developed a mixed pattern of liver injury. Median onset of liver injury was 5.5 days.

Discussion: In prior case reports and animal studies, these cases suggest imidacloprid toxicity is associated with liver injury that may be delayed. This is consistent with our finding. The cases also demonstrated a possible dose-response relationship of imidacloprid ingestion with severity and type of liver injury. All findings suggested that imidacloprid might contribute to liver injury.

Conclusion: We report four cases of liver injury, which are possibly related to ingestion of imidacloprid. In management, consideration should be given to repeating liver tests as an outpatient if initial tests are normal, with counseling on the possibility of delayed liver injury.

Keywords:

• Imidacloprid
• neonicotinoid
• hepatotoxicity
• liver toxicity
• liver injury

Acknowledgments

The authors would like to thank Dr. Surasak Thirapattarapan from Chaophrayayommaraj Hospital for his assistance in gathering relevant data. One case in this study was presented at the 11th Asia Pacific Association of Medical Toxicology (APAMT) Congress meeting (November 29 to December 1, 2012, Hong Kong) as poster presentation on the topic “Liver toxicity of acute poisoning by imidacloprid ingestion in human: a case report.” In addition, the abstract of this article was presented at the North American Congress of Clinical Toxicology (NACCT 2015) meeting (October 8–12, 2015, San Francisco, USA) as a poster presentation with interim findings.

Disclosure statement

The authors declare no conflicts of interest.

Data availability statement

The data are not available for public access because of patient privacy concerns but are available from the corresponding author on reasonable request.