Opioid rotation for cancer pain

When pain is relieved inadequately by opioid analgesics given in a dose that causes intolerable side effects despite routine measures to control them, treatment with the same opioid by an alternative route or with an alternative opioid administered by the same route should be considered. Opioid rotation may be useful in opening the therapeutic window and for establishing a more advantageous analgesia/toxicity relationship. By substituting opioids and using lower doses than expected according to the equivalency conversion tables, it is possible in the majority of cases to reduce or relieve the symptoms of opioid toxicity in those patients who were highly tolerant to previous opioids while improving analgesia and, as a consequence, the opioid responsiveness.