| Morphine vs Hydromorphone vs Oxycodone vs the Fentanyl Patch Downloadable PDF file|
Re-issued by Dr. Doreen Oneschuk, Editor. Grey Nuns Community Hospital. Original Contributor: Paul Walker, MD - Issue #17 (Collect them all) February, 2004.
The spectrum of available opioids has increased. Why do we need alternative opioids?
o Concept of individual variability in opioid response
- relative intensity of analgesic and toxic effects
- spectrum of toxicities experienced
varies with different opioids within the same individual and between different individuals on the same opioid
May be due to:
•Genetically - determined expression of opiate receptor subtypes
•Incomplete cross-tolerance 2nd to differential receptor subtype affinity or efficacy
• Opioid metabolite accumulation
•Pain mechanism - specific opioid response
Recent proliferation of reports -->improvement in analgesia-toxicity balance with opioid switch.
Morphine: (immediate release - Morphine HP, Statex, MOS, MS-IR, Morphitec; slow release - MS Contin, M-Eslon, MOS-SR, Oramorph SR, Kadian)
• preferred routes: oral, subcutaneous, rectal
•the standard/benchmark opioid, usual first choice
•10x more potent mg for mg than codeine
•parenteral maximum concentration: 50 mg/ml
Hydromorphone: (immediate release - Dilaudid, PMS-Hydromorphone; slow release - Hydromorph Contin)
• preferred routes: oral subcutaneous, rectal
•approx. 5x more potent mg for mg than morphine
•parenteral maximum concentration: 100 mg/ml
•the usual alternative to morphine
Oxycodone: (immediate release - Supeudol; slow release - OxyContin)
•preferred routes: oral subcutaneous, rectal
•originally introduced in combination with ASA (Percodan, Oxycodan, Endodan) or Acetaminophen (Percocet, Oxycocet, Endocet, Roxicet) for moderate pain.
•hallucinations reported in studies.
•approx. 1.5x more potent mg for mg than morphine (controversial)
•parenteral maximum concentration: 50-60 mg/ml
Fentanyl: (transdermal - Duragesic; parenteral - Sublimaze)
•high lipid solubility
•50-100x as potent as morphine
•transdermal patch convenient in patients with stable pain control. Caution advised in uncontrolled pain syndromes (not suitable for rapid titration)
• possible in constipation and sedation
•GI withdrawal syndrome described with switch to patch
•conversion ratio uncertain (use published conversion table)
•no convenient form for rescue doses
•subcutaneous infusions pump needed for continuous infusion high cost of drug
Consider switching drug when opioid toxicity develops eg: sedation, delirium, hallucinations, myoclonus. calculate an equianalgesic daily dose of the new opioid, reduce this by 20-30% to account for incomplete cross tolerance between opioids, divide into multiple daily doses at regular intervals (q4h for immediate release opioids). Provide approx. 10% of the total daily dose available as a rescue dose.REMEMBER: For referrals, questions, or telephone consultations call 496-1300 weekdays and weekends