Paper I
Question
Tramadol
Answer
Tramadol is a centrally-acting analgesic with a dual mechanism of action.
Mechanism of action
- Weak agonist at μ-opioid receptors
- Also inhibits reuptake of serotonin and noradrenaline in the descending pain-inhibitory pathways, contributing to its analgesic effect
- This dual mechanism gives analgesia comparable to moderate-strength opioids with somewhat lower abuse/dependence potential
Uses
- Moderate to moderately severe pain (postoperative pain, cancer pain, chronic pain)
Adverse effects
- Nausea, vomiting, dizziness
- Sedation
- Seizures (lowers seizure threshold, especially with other pro-convulsant drugs)
- Serotonin syndrome (risk with SSRIs/MAO inhibitors)
- Dependence potential (lower than morphine but present)
- Respiratory depression (less than full opioid agonists at usual doses)