What are the morphine equivalents of 10mg Targin (oxycodone/naloxone) versus 800mcg buprenorphine sublingual in a patient with no significant renal or hepatic impairment?

Morphine Equivalent Comparison: 10mg Targin vs 800mcg Buprenorphine Sublingual

10mg Targin (oxycodone/naloxone) provides approximately 15-20mg oral morphine equivalents, while 800mcg (0.8mg) sublingual buprenorphine provides approximately 60mg oral morphine equivalents—making buprenorphine sublingual roughly 3-4 times more potent than this dose of Targin.

Calculation for Targin (Oxycodone Component)

• Targin 10mg contains 10mg oxycodone (the naloxone component does not contribute to systemic analgesia when taken orally as intended)
• Oxycodone has 1.5-2 fold potency compared to oral morphine 1
• Morphine equivalent = 10mg × 1.5-2 = 15-20mg oral morphine 1

Calculation for Buprenorphine Sublingual

• Sublingual buprenorphine has 75-fold potency compared to oral morphine according to ESMO cancer pain guidelines 1
• Morphine equivalent = 0.8mg × 75 = 60mg oral morphine 1
• This conversion factor is specifically validated for sublingual administration 1

Critical Caveats About Buprenorphine Conversion

The 75-fold conversion ratio represents a guideline estimate, but buprenorphine's partial agonist properties make direct equivalency calculations less reliable than with full agonists. 1

• Buprenorphine's high mu-receptor affinity but partial activation creates a ceiling effect for respiratory depression (though not necessarily for analgesia at higher doses) 1
• The 90% first-pass hepatic metabolism of sublingual buprenorphine means bioavailability varies significantly between individuals 1
• Clinical experience suggests buprenorphine may provide less predictable analgesia than calculated morphine equivalents would suggest, particularly during acute pain episodes 1

Practical Clinical Implications

When switching between these medications, reduce the calculated equianalgesic dose by 25-50% to account for incomplete cross-tolerance. 1, 2

• If converting from 10mg Targin to buprenorphine sublingual: The calculated equivalent would be approximately 0.2-0.27mg buprenorphine, but start with 0.1-0.15mg (100-150mcg) and titrate upward 1, 2
• If converting from 800mcg buprenorphine to Targin: The calculated equivalent would be approximately 30-40mg oxycodone, but start with 15-25mg and titrate based on response 1, 2

Important Safety Considerations

• Never combine buprenorphine with mixed agonist-antagonists (pentazocine, nalbuphine, butorphanol) as this precipitates withdrawal 3
• Patients on 800mcg sublingual buprenorphine are opioid-tolerant and at risk for withdrawal if switched abruptly to the much lower equivalent Targin dose 3
• The 800mcg buprenorphine dose is at the upper end of typical analgesic dosing (usual range 0.4-4mg daily for pain) and suggests either opioid use disorder treatment or high opioid tolerance 1