AKT-3152

A 25-year-old man was prescribed fluoxetine for a depressive illness related to a recent breakup. You receive a call one week later from his family, stating that he has become very ill after increasing his dose without medical advice. Upon visiting him, you observe that he is confused, sweating profusely, and has a fever of 39.5°C. He is experiencing tremors and myoclonus, but no other physical symptoms. He denies taking any other medications or substances. What is the most likely cause of his symptoms?