Rare Presentation of Organophosphorus Poisoning Induced Diabetes Insipidus: A Case Report

Organophosphorus Compounds (OPC) are widely used insecticides that pose significant health risks following intentional or accidental consumption. The effects of organophosphates on the central nervous system include irritability, restlessness, disorientation and confusion, which can progress to generalised seizures, status epilepticus and brain damage. Diabetes insipidus is a rare and unusual complication of organophosphorus poisoning. In this case study, a patient with organophosphate poisoning who was admitted to the Emergency Department (ED) with an alleged history of exposure to the OPC Chlorpyrifos 1.5% is presented. Upon admission, her Glasgow Coma Scale (GCS) score was 7/15 and she exhibited anisocoria (right pupil 4 mm and left pupil 2 mm) with sluggishly reacting pupils to light. She was immediately started on an atropine infusion, but later developed tachycardia and seizures, which were treated appropriately. Her electrolytes were abnormal, revealing hypernatremia (serum Na+ 182 mEq/L) and she was treated to reduce this condition. Additionally, the patient was monitored for urine output, which measured 250-350 mL/hr, with a serum osmolality of 379 mOsm/kg and a urine spot sodium of 243 mEq/L. Based on these findings, she was diagnosed with diabetes insipidus and started on desmopressin. However, her GCS showed no improvement and eventually decreased to 2T/15, indicating a poor prognosis. In conclusion, this case study suggests that diabetes insipidus is a rare transient complication of OPC poisoning. This idiosyncratic effect is uncommon and physicians should be aware of such complications and treat them accordingly.