Review Question - QID 210371

A 34-year-old woman presents to the emergency room with a fever. She developed worsening malaise and diaphoresis over the past 48 hours. Her maximum temperature was 102°F (38.9°C) taken the night before presentation. Her past medical history is notable for major depressive disorder, obesity, fibromyalgia, and severe tension headaches. She previously took paroxetine for a 2-month trial but switched to citalopram 6 months ago as she did not feel like paroxetine was adequately helping her symptoms. Her mood has been stable on her current dose of citalopram. She takes ibuprofen for her headaches but previously borrowed a friend’s headache medication when her headaches became very severe. Of note, she has been trying to lose weight and recently started taking an amino acid supplement at the suggestion of her nephew who is a nutritionist. She is also trying out a new low-carbohydrate diet. She works as a nurse at a local primary care clinic. Her temperature is 101.5°F (38.6°C), blood pressure is 144/80 mmHg, pulse is 108/min, and respirations are 22/min. She is diaphoretic and shivering. Patellar and brachioradialis reflexes are 3+ bilaterally. Tone is increased in her bilateral upper and lower extremities. Rapid dorsiflexion of her right ankle elicits 3 beats of clonus. Pupils are equally round and reactive to light. A basic metabolic panel is within normal limits. Which of the following is the most likely inciting factor for this patient’s condition?