Human Zinc Phosphide Exposure in Lebanon: A Case Report and Review of the Literature

Toxicity from rodenticides such as metal phosphides is common worldwide, particularly in developing countries where consumers have access to unlabeled and uncontrolled insecticides and pesticides.

We present the first documentation of a metal phosphide exposure in Lebanon. A middle-aged woman presented to the emergency department following the ingestion of an unknown rodenticide. Spectroscopy analysis of the sample brought by the patient was used and helped identify zinc phosphide. The patient developed mild gastrointestinal symptoms and was admitted to the intensive care unit for observation without further complications.

We subsequently conducted a literature review to understand the diagnosis, pathophysiology, clinical presentation, and management of metal phosphide toxicity. Multiple searches were conducted on MEDLINE and PubMed, and articles related to the topics under discussion were included in the review. Metal phosphide is associated with significant morbidity and mortality involving all body systems. Patients presenting with metal phosphide intoxication need extensive workup including blood testing, electrocardiogram, and chest radiography. To date there is no antidote for metal phosphide toxicity, and management is mostly supportive. Many treatment modalities have been investigated to improve outcomes in patients presenting with metal phosphide toxicities.

Emergency physicians and toxicologists in developing countries need to consider zinc and aluminum phosphides on their differential when dealing with unlabeled rodenticide ingestion. Treatment is mostly supportive with close monitoring for sick patients. Further research is needed to better understand metal phosphide toxicity and to develop better treatment options.