A 45-year-old male presents to the psychiatric emergency department with complaints of altered mental status, confusion, agitation, tremors, and sweating. His significant other, who accompanies him, reports that the patient has been acting strangely for the past few days, appearing more anxious and restless than usual. They also state that he has been sweating profusely and experiencing tremors in his hands.Medical History: The patient has a history of chronic lower back pain and depression. He has been taking duloxetine 60mg once daily and sertraline 200mg once daily for the past year for his depression. He suffered a torn ligament in his right knee after a fall one week ago and was prescribed tramadol 50mg every 6 hours prn by his primary care physician.Physical Examination: Upon examination, the patient appears agitated and diaphoretic. He is tachycardic with a heart rate of 110 beats per minute and hypertensive with a blood pressure of 160/100 mmHg. He is also noted to have myoclonus and hyperreflexia. His pupils are dilated and he is experiencing muscle rigidity, particularly in his lower extremities.
What is the most probable cause of this patient's symptoms and why?