Tramadol is an analgesic drug used to treat moderate to severe pain. Tramadol provides pain relief by acting as a weak agonist at mu opioid receptors, and also by inhibiting the reuptake of norepinephrine and serotonin at neuronal synapses. Side effects of tramadol include the classic constellation of side effects seen in all opioids, such as constipation, sedation, and miosis. However, specific and important side effects include seizures, as well as precipitation of serotonin syndrome, especially if tramadol is given with other serotonin-modulating drugs.

Key Points

  • Tramadol
    • Mechanism
      • Weak opioid agonist
      • Increases signaling by norepinephrine (NE) and serotonin (5-HT)
        • Via reuptake inhibition
    • Clinical Uses
      • Analgesia
    • Adverse Effects
      • Opioid-related effects
        • Includes constipation, miosis, respiratory depression, etc.
      • Decreases seizure threshold
      • Serotonin syndrome
        • Seen in any drug that modulates serotonin levels
        • Especially if used with other serotonergic drugs (e.g. TCAs, MAOIs, SSRIs)