Although methodological limitations were found in
these three studies, data consistently show no signifi cant
diff erences in analgesic effi cacy between methadone and
morphine; the evidence of more frequent CNS sideeff
ects (sedation) with methadone is not consistent across
studies. Methadone should be considered an alternative
to other oral step III opioids.
Recommendation for use of methadone
Methadone has a complex pharmacokinetic profi le with
an unpredictably long half-life. The data permit a weak
recommendation that it can be used as a step III opioid
of fi rst or later choice for moderate to severe cancer pain.
It should be used only by experienced professionals.