Quigley, C. (2008). Opioids in people with cancer-related pain. Clinical Evidence, 2008, 2408.

 

To determine the effects of various opioids in treating cancer-related pain

• Databases searched were MEDLINE, EMBASE, the Cochrane Library, National Health Service Centre for Reviews and Dissemination, Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment (HTA), Turning Research into Practice (TRIP), and National Institute for Clinical Excellence (NICE).
• Authors did not include search keywords in the report.
• Studies were included if they
  • Were systematic reviews or randomized controlled trials whose results were published in any language.
  • Included more than 20 participants, of whom investigators followed up with 50%.
• Authors did not list exclusion criteria.

Investigators reviewed 34 studies. Investigators used 22 studies as the basis of their report. Investigators evaluated studies by performing a GRADE evaluation of the evidence, using the following criteria: type of evidence, quality, consistency (similarity of results across studies), directness (generalizability), and effect size. Evidence ratings were very low, low, moderate, and high.

• Authors did not specify total sample size.
• The sample included patients with cancer-related pain.

Authors reported results relative to pain, need for rescue analgesia, function, quality of life, patient preference, and adverse events.

Morphine is the standard opioid in the management of moderate to severe cancer pain. Evidence from this study was insufficient to allow authors to compare other opioids to it. Evidence from this study was insufficient to allow conclusions about codeine. Investigators categorized the effectiveness of dihydrocodeine, a newer option for pain control, as unknown. Evidence from this study was insufficient to allow authors to rate the effectiveness of transdermal fentanyl. Hydromorphone may be as effective as morphine or oxycodone and may cause fewer adverse effects. Methadone may be as effective as morphine or oxycodone, for reducing pain, and the two opioids' rates of associated adverse effects are similar. Oxycodone and morphine may be equally effective in reducing pain. Tramadol may be as effective as morphine, but morphine seems to have quicker onset.

Authors deemed all evidence cited in this review to be of very low or low quality.