Consider the following metabolic pathway and answer the ques…

Consider the following metabolic pathway and answer the question below:                                  Which of the following molecules best fits in box 23? (chemically, not physically)                                 

An epileptic patient who was stabilized on carbamazepine (80…

An epileptic patient who was stabilized on carbamazepine (800 mg/day) became severely depressed and was prescribed fluoxetine (SSRI) to treat the patient’s depressive disorder. After two weeks, neurotoxicity became apparent that was more suggestive of serotonin syndrome than of carbamazepine toxicity. A measurement of serum levels of fluoxetine showed 4 times the typical serum concentration.  Carbamazepine is a known inducer of CYP3A4.  Fluoxetine is chiefly metabolized by CYP2D6. The physician is considering switching antiseizure medications but it took considerable trial and error with multiple drugs to get the patient’s seizures under control.  Which of the following has the greatest likelihood of causing the elevated fluoxetine levels?