Which agents can cause serotonin syndrome?

• A. Antidepressants, St. John's Wort, SAM-e, Kava Kava, and Tryptophan
• B. Only antibiotics
• C. Only vitamin supplements
• D. Non-steroidal anti-inflammatory drugs

Answer: (A)

Serotonin syndrome arises when there is excessive serotonergic activity in the brain, usually from combining multiple drugs that boost serotonin or taking supplements that increase serotonin levels. Antidepressants raise brain serotonin directly by inhibiting reuptake or increasing release, so they are common contributors. Herbal and supplemental agents like St. John’s Wort, SAM-e, and tryptophan either boost serotonin production or signaling and can interact with other serotonergic meds to push levels higher. Tryptophan is a direct precursor to serotonin, so adding it to a serotonergic regimen can significantly elevate serotonin. Kava kava has effects on neurotransmitter systems that can augment serotonergic activity as well, especially when used with other serotonergic agents. Taken together or at high doses, these agents can trigger serotonin syndrome, which is why this broad combination is the correct answer.