What dose of tramadol (opioid analgesic) is equivalent to 5mg of oxycodone (opioid analgesic) for pain management?

Tramadol Dose Equivalent to 5 mg Oxycodone

50 mg of tramadol is approximately equivalent to 5 mg of oxycodone for pain management. This equivalence is based on the CDC's opioid conversion factors, which indicate that tramadol has a conversion factor of 0.2 and oxycodone has a conversion factor of 1.5 when calculating morphine milligram equivalents (MME) 1.

Understanding the Conversion

When converting between opioids, it's important to understand the relative potency:

• 5 mg oxycodone = 7.5 MME (5 × 1.5 conversion factor)
• To achieve 7.5 MME with tramadol (conversion factor 0.2), you need: 7.5 ÷ 0.2 = 37.5 mg
• In clinical practice, this is rounded to 50 mg of tramadol, which is the standard available dosage

Pharmacological Differences

Despite the MME conversion, there are important differences between these medications:

• Mechanism of action:

  • Oxycodone is a full μ-opioid receptor agonist
  • Tramadol is a weak μ-opioid receptor agonist that also inhibits reuptake of serotonin and norepinephrine 1

• Potency:

  • Tramadol is considered approximately one-tenth as potent as morphine 1
  • Oxycodone is 1.5 times as potent as morphine 1

Clinical Considerations

When choosing between these medications, consider:

1. Pain type:

   • Tramadol may be particularly useful for neuropathic pain components due to its dual mechanism of action 1
   • Oxycodone is typically more effective for severe nociceptive pain

2. Side effect profiles:

   • Tramadol has lower risk of respiratory depression but higher risk of seizures and serotonin syndrome, especially when combined with other serotonergic medications 1
   • Oxycodone has higher risk of constipation, respiratory depression, and physical dependence 2

3. Maximum daily doses:

   • Tramadol: Maximum 400 mg/day (100 mg 4 times daily) 1
   • Oxycodone: No absolute maximum but requires careful titration with increasing vigilance at doses ≥50 MME/day 1, 2

Special Populations

• Elderly patients (>75 years): Reduce tramadol dosage to 300 mg/day maximum 1
• Renal/hepatic impairment: Both medications require dose adjustment; tramadol may require more significant reduction 1

Important Cautions

• Risk of dependence: While tramadol has lower abuse potential than oxycodone, both medications can cause physical dependence 3
• Drug interactions: Tramadol has significant interactions with SSRIs, SNRIs, and MAOIs due to risk of serotonin syndrome 1
• CDC guidance: The CDC recommends caution when prescribing opioids at any dosage and avoiding dose increases when possible. Before increasing total opioid dosage to ≥50 MME/day, clinicians should carefully reassess evidence of individual benefits and risks 1

Remember that these conversions are estimates and individual patient responses may vary. When switching between opioids, it's generally recommended to start with a lower equivalent dose (typically 25-50% reduction) due to incomplete cross-tolerance and individual variability in opioid pharmacokinetics 1.