Opioids combined with antidepressants or antiepileptic drugs for cancer pain: Systematic review and meta-analysis.

Background: Combining antidepressant or antiepileptic drugs with opioids has resulted in increased pain relief when used for neuropathic pain in non-cancer conditions. However, evidence to support their effectiveness in cancer pain is lacking.

Aim: To determine if there is additional benefit when opioids are combined with antidepressant or antiepileptic drugs for cancer pain.