A Case of Pendimethalin Toxicity Mimicking Organophosphorus Toxicity

Introduction: Pendimethalin is an herbicide that is used worldwide to attack certain wide leaf and grassy weeds in a variety of agricultural and non-crop regions, with a claimed very low toxicity to human. There have been some few reported cases of acute pendimethalin toxicity to date, around the world. We report a case of pendimethalin toxicity resembling and managed initially as organophosphorus poisoning. Case Description: A ۴۲-year-old agricultural worker was found unresponsive in his field with profuse oral secretions. The patient presented with altered mental status, where Glasgow comma scale was ۱۰, oxygen saturation at room air was ۸۸ %, Blood pressure measured ۱۲۵/۷۵, pulse rate was ۹۵ beats per minute, and temperature was ۳۷ °C. The patient’s pupils were constricted, equal, regular, and reactive. Chest examination revealed scattered respiratory crepitations. The patient also had a distinct garlic odor very similar to that of Organophosphate compounds. The results of his laboratory investigations revealed only hypoxemia. The patient received atropine and supportive management, which prompted the chest secretions to clear up and allow him to restore consciousness without experiencing any neurological problems.Conclusion: Pendimethalin toxicity can present with manifestations mimicking acute organophosphorus poisoning. Proper supportive care is needed for the management of acute pendimethalin toxicity.