Oh wait … It isn’t MUDPILES! Acute toxic encephalopathy with an interesting anion gap metabolic acidosis resulting in prolonged invasive mechanical ventilation

A 70-year-old white female patient with past medical history of migraine, fibromyalgia, diverticulitis, and hypothyroidism presented to the emergency department accompanied by her husband for one day of altered mentation, nausea and vomiting. Laboratory testing showed oligo-anuric acute kidney injury with a severely high anion gap metabolic acidosis. Urine drug screen was negative. Brain imaging and lumbar puncture were negative for acute findings. We report this unique case by going through the differential for anion gap metabolic acidosis secondary to Celecoxib as well as a unique drug–drug interaction between Celecoxib and Gabapentin.