Serotonin: Agonists, Antagonists, and Reuptake Inhibitors

Uses

• Serotonin (5-hydroxytryptophan [5-HT]) not given as a drug; is a neurotransmitter that plays many roles within the body; serotonin levels can be affected by drugs called serotonin agonists and antagonists

• Partially selective receptor agonists used mostly for Rx of acute migraine headaches; they include:

  • Sumatriptan (Imitrex) 5–20 mg IN, 25–100 mg/d PO

  • Naratriptan (Amerge) 2.5 mg/d PO

  • Rizatriptan (Maxalt) 5 mg/d PO

  • Zolmitriptan (Zomig) 5 mg IN, 2.5 mg/d PO

• Partially selective receptor 5-HT ₃ antagonists used to treat N/V

  • Metoclopramide (Reglan) 5–15 mg qid PO, 2–10 mg IV, 10–20 mg IM (used to treat GERD, gastroparesis, N/V)

  • Dolasetron (Anzemet) 12.5 mg IV or 100 mg PO 30–60 min before emergence to prevent postop N/V or before chemotherapy

  • Ondansetron (Zofran) 4–8 mg tid PO to prevent N/V due to emergence or emetogenic chemotherapy treatment

  • Granisetron (Kytril) 10 μg/kg IV, 1 mg bid PO, TD patch (Sancuso) for prevention of N/V due to chemotherapy and for postop N/V

  • Palonosetron (Aloxi) 0.25 mg IV 30 min before and days after chemotherapy

• SSRIs (all used PO to treat major depression and personality disorders (e.g., OCD, PTSD)

  • Citalopram (Celexa) 20–40 mg/d PO (fewest side effects)

  • Escitalopram (Lexapro) 10 mg/d PO

  • Fluoxetine (Prozac, Sarafem) 20–80 mg/d PO

  • Paroxetine (Paxil, Pexeva) 20–50 mg/d PO

  • Sertraline (Zoloft) 50–200 mg/d PO (least tolerated)