A 40-year-old male on paroxetine for depression presents to the emergency department with agitation, confusion, hyperreflexia, diaphoresis, and tremor. He recently started a new medication for migraine headaches. Which of the following medications, if recently added, would most likely explain his current symptoms?

Explanation

The patient's symptoms (agitation, confusion, hyperreflexia, diaphoresis, tremor) are classic for serotonin syndrome. Serotonin syndrome is a potentially life-threatening condition caused by excessive serotonergic activity in the central nervous system. Paroxetine is an SSRI, which increases serotonin levels. Sumatriptan (a triptan) is a 5-HT1B/1D receptor agonist used for migraines, and it also increases serotonergic activity. The combination of an SSRI and a triptan can lead to an additive effect, precipitating serotonin syndrome. Propranolol (a beta-blocker), ibuprofen (an NSAID), and amoxicillin (an antibiotic) do not significantly interact with serotonin pathways to cause serotonin syndrome.