Opioids are recommended for control of moderate-to-severe, chronic, malignant, and nonmalignant
pain. A
controlled-release formulation of the
opioid oxymorphone has recently been launched. The aim of this review was to assess the effectiveness of
oxymorphone as an
analgesic in
chronic pain. A systematic search for published studies of oral
oxymorphone in the management of chronic
pain was conducted. The studies were evaluated for their internal validity according to standard criteria. They were also evaluated for their external validity and research ethic aspects. A meta-analysis was performed to examine the effect of
oxymorphone compared with placebo. Nine studies were evaluated; three were excluded because of low quality. Six controlled studies (duration 2-12 weeks) included a total of 1489 subjects suffering from chronic
low back pain,
chronic pain from
osteoarthritis, and chronic
cancer pain. Three of the studies were of high quality and three of medium quality. External validity was assessed to be high, medium, and low (in one, three, and two studies, respectively). The meta-analysis suggests that daily doses of 40-100mg are superior to placebo; however, the estimate (reduction of
pain intensity compared with placebo) of the treatment effect is imprecise (95% confidence interval -17.08, -8.69). Limited evidence suggests that
oxymorphone is effective for
pain control in patients with
cancer. No significant differences between
oxymorphone and
oxycodone at equipotent doses were found. In conclusion,
oxymorphone is superior to placebo. There is no evidence that the efficacy of
oxymorphone differs from other
opioids.