102 PCN Guidelines for Opioid Rotation

• Select the new drug on the basis of pharmacologic features, previous experience, availability, cost
• Calculate the equianalgesic dose:
  • If switching to any opioid other than methadone of fentanyl:
    • Plan dose reduction of 25-50% (incomplete cross tolerance)
    • Select dose reduction closer to 50% if higher dose, elderly, medically frail
  • If switching to methadone:
    • Dose reduction is 50-75%, rarely converting to methadone at dose higher than 100 mg/day
  • If switching to transdermal fentanyl:
    • Use calculated equianalgesic dose included in product information (approx. OME/2)

On the basis of assessment of severity of pain severity and other medical/psychologic characteristics, increase or decrease the calculated dose by 15-30% to increase the likelihood that the initial dose will be effective, or conversely, unlikely to cause withdrawal or side-effects

If a supplemental (breakthrough) dose is used, calculate this dose at 10-20% of the total daily dose (OME) and administer at an appropriate interval

Exception: transmucosal fentanyl formulations should always be initiated at lower doses and titrated