Successful pain management with opioids requires that adequate
analgesia be achieved without excessive adverse effects. By these
criteria the application of the WHO and the EAPC guidelines (using
morphine as the preferred step 3 opioid) permit effective control of
chronic cancer pain in the majority of patients. In a small minority of
patients adequate relief without excessive adverse effects may depend
on the use of alternative opioids, spinal administration of analgesics or
non-drug methods of pain control.