Objective Studies on the acute toxicity of pendimethalin herbicide in humans are limited. Therefore, this study investigated the clinical characteristics of acute intentional pendimethalin herbicide poisoning.

Material and method A retrospective observational case series was conducted involving 17 patients with a history of intentional pendimethalin herbicide ingestion. Data were collected on clinical manifestations, management and final outcome.

Result The mortality rate was 0%; however, four patients (23.5%) exhibited metabolic acidosis, hypotension or respiratory failure within the first 24 h after ingestion and required admission to the intensive care unit. The most common complication was respiratory failure, followed by hypotension. Complicated patients tended to show an altered mental state and X-ray abnormalities at presentation.

Discussion and conclusions Physicians should be aware that patients who have been poisoned with pendimethalin herbicide, and particularly patients with a depressed mental state and X-ray abnormalities at presentation, may exhibit metabolic acidosis, hypotension, respiratory failure or pancreatitis.